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Haptoglobin is a glycoprotein which is synthesized in the liver and circulates in the blood. Haptoglobin is produced typically by hepatocytes but also by other tissues: e.g. skin, lung, and kidney. It is a positive acute phase protein that binds free hemoglobin and removes it from the circulation to prevent kidney injury, and iron loss following hemolysis. The haptoglobin-hemoglobin complex is subsequently removed by the reticuloendothelial system (generally the spleen). As the reticuloendothelial system removes the haptoglobin-hemoglobin complex from the body, haptoglobin levels are reduced in hemolytic anaemias. In the course of binding hemoglobin, haptoglobin sequesters the iron inside hemoglobin, preventing iron-utilizing bacteria from benefitting from hemolysis.
Haptoglobin consists of two A- and two B-chains, connected by disulfide bonds. Three major haptoglobin phenotypes are known to exist (Hp 1-1, Hp 2-1, and Hp 2-2). Hp 1-1 is biologically the most effective in binding free hemoglobin and suppressing inflammatory responses associated with free hemoglobin. Hp 2-2 is biologically the least active, and Hp 2-1 is moderately active. Haptoglobin’s molecular mass ranges from 8-200 kDa.
Reduced levels can be seen in haemolysis and impaired liver function. High levels are a marker for acute or chronic inflammation. Ahaptoglobinemia or hypohaptoglobinemia are caused by mutations in the haptoglobin gene and/or its regulatory regions. Haptoglobin is also linked to diabetic nephropathy, the incidence of coronary artery disease in type 1 diabetes, Crohn's disease, inflammatory disease behavior, primary sclerosing cholangitis, susceptibility to idiopathic Parkinson's disease, and a reduced incidence of Plasmodium falciparum malaria.

Reticulocalbin 3 (RCN3) belongs to the CREC (cab45/reticulocalbin/ ERC45/calumenin) family. RCN3 contains 5 Arg-Xaa-Xaa-Arg motifs, which function as target sequences of SPCs (subtilisin-like proprotein convertases), which is a family of serine endoproteases that proteolytically activate proproteins. The synthesis of PACE4 is induced by association and coexpression with RCN3.

Leptin is a protein hormone. It is mainly produced in adipose cells that regulate energy homeostasis by restraining hunger. Leptin ties to nuclear receptors in the hypothalamus (arcuate nucleus). Similar to insulin resistance in type II diabetes, in obesity there is a decrease in the sensitivity towards leptin, ending in a failure to identify satiety, even in high levels of energy stores or leptin itself. Full-length cDNA encoding 2 leptin sequences (tLepA and tLepB) and 1 leptin receptor sequence (tLepR) exists in tilapia (Oreochromis niloticus). The full-length cDNA of tLepR is 3423 bp, encoding a protein of 1140 amino acid which contained all functionally important domains conserved among vertebrate leptin receptors. The cDNAs of tLepA and tLepB are 486 bp and 459 bp in length, encoding proteins of 161 aa and 152 aa, respectively. The three-dimensional structures of tLepA and tLepB demonstrates strong conservation of tertiary structure with that of human leptin comprised of 4 helixes.

CD44 is a cell-surface glycoprotein that plays a role in cell-cell interactions, cell adhesion and migration. CD44 is a receptor for hyaluronic acid and also interacts with other ligands, such as osteopontin, collagens, and matrix metalloproteinases. CD44 participates in a wide variety of cellular functions such as lymphocyte activation, recirculation and homing, hematopoiesis, and tumor metastasis.

The recombinant Protein A/G is a genetically engineered protein comprised of 7 IgG-binding domains EDABC-C1C3, corresponding to the Protein A and G domains which are included in the recombinant sequence. The Protein A part is from Staphylococcus aureus segments E, D, A, B and C. The Protein G part is from Streptococcus segments C1 and C3. The recombinant Protein A/G has a broader binding capacity than either Protein A or Protein G alone. The recombinant Protein A/G is ideal for purification of monoclonal or polyclonal IgG antibodies. Protein A/G binds to various human, mouse and rat IgG subclasses such as the human IgG1, IgG2, IgG3, IgG4; mouse IgG2a, IgG2b, IgG3 and rat IgG2a, IgG2c. In addition, Protein A/G binds to total IgG from cow, goat, sheep, horse, rabbit, guinea pig, pig, dog and cat.

Human immunodeficiency virus type-1 (HIV-1) regulatory Tat protein plays an essential role in viral replication and infectivity. In addition, during acute infection, Tat is released extracellularly by infected cells and is taken up by neighboring cells where it transactivates viral replication and increases virus infectivity.
HIV-1 Tat activates transcription of HIV-1 viral genes by inducing phosphorylation of the C-terminal domain (CTD) of RNA polymerase II (RNAPII). Tat can also disturb cellular metabolism by inhibiting proliferation of antigen-specific T lymphocytes and by inducing cellular apoptosis. Tat-induced apoptosis of T-cells is attributed, in part, to the distortion of microtubules polymerization. LIS1 is a microtubule-associated protein that facilitates microtubule polymerization.

MCSFR which is also familiar as CSF1R, is part of the type3 subfamily of receptor tyrosine kinases. MCSFR is expressed mainly on cells of the monocyte and macrophage lineage, stem cells, and in the growing placenta. Most of the biological effects of this cytokine are mediated by MCSFR. MCSFR contains an extracellular ligand-binding domain, a single membrane-spanning segment, and an intracellular tyrosine kinase domain. Originally CSF1 and this receptor were implicated as vital for normal trophoblastic implantation as well as monocyte development. The role of CSF1/CSF1R in normal mammary gland development is actually very interesting since this connection has also been discovered in the biology of breast cancer with the results of abnormal expression of CSF1 and its receptor. Likewise, in Alzheimer's disease and after brain injuries an increased level of CSF1R was found in the microglia, which causes the microglia to become more active.

GM-CSF Receptor Alpha (CSF2RA) is the alpha subunit of the heterodimeric receptor for colony stimulating factor 2, a cytokine which controls the production, differentiation, and function of granulocytes and macrophages. CSFR2 is also a member of the cytokine family of receptors. In addition, this gene is found in the pseudoautosomal region (PAR) of the X and Y chromosomes. Multiple transcript variants encoding various isoforms have been found for this gene, while some of the isoforms being membrane-bound and others being soluble. Diseases associated with CSF2RA include surfactant metabolism dysfunction, pulmonary 4, and csf2ra-related pulmonary surfactant metabolism dysfunction.

ITGB4 (integrin beta-4 isoform 1) belongs to the Integrin beta family. ITGB4 forms noncovalent heterodimers with Integrin alpha 6 and takes part in the formation of epithelial hemidesmosomes. ITGB4 has a vital structural role in the hemidesmosome of epithelial cells and is needed for the regulation of keratinocyte motility & polarity. ITGB4 leans towards the association with alpha 6 subunit and is expected to take a key role in the biology of invasive carcinoma.

FSTL1 protein resembles follistatin, an ACTV-binding protein. FSTL1 is an autoantigen associated with rheumatoid arthritis and it holds an FS section, a follistatin-like sequence having 10 conserved cysteine residues.

Trafficking protein particle complex 4 (TRAPPC4) is part of the multisubunit TRAPP (transport protein particle) complex and interacts with SDC2. TRAPPC4 has a role in vesicular transport from endoplasmic reticulum to Golgi.

M-phase inducer phosphatase 1 (CDC25A) belongs to the CDC25 family of phosphatases. CDC25A is essential for progression from G1 to the S phase of the cell cycle. CDC25A activates the cyclin-dependent kinase CDC2 by eliminating 2 phosphate groups. CDC25A is specifically degraded in reaction to DNA damage, which inhibits cells with chromosomal abnormalities from progressing in the course of cell division. CDC25A is an oncogene, though its exact function in oncogenesis has not been determined.

BETV4 is primarily expressed in mature birch (Betula verrucosa) pollen and Causes an allergic reaction in human. BETV4 is a calcium-binding protein of 2-EF-hand type, which is exists in pollen of various plant species. This cross-reactivity can serve as a marker allergen for plant polysensitization.

TRIM21 is a member of the tripartite motif (TRIM) family. The TRIM motif includes three zinc-binding domains, a RING, a B-box type 1 and a B-box type 2, and a coiled-coil region. The 52 kDa Ro protein is part of the RoSSA ribonucleoprotein, which includes a single polypeptide and one of four small RNA molecules. The RoSSA particle localizes to both the cytoplasm and the nucleus. Ro/SSA interacts with autoantigens in patients with Sjogren syndrome and systemic lupus erythematosus. Ribonucleoprotein particle is composed of a single polypeptide and one of four small RNA molecules. The RoSSA is present in all mammalian cells studied but has no known function. At least 2 isoforms are present in nucleated and red blood cells, and tissue specific differences in Ro/SSA proteins were identified.

CTSW protein belongs to the peptidase C1 family. CTSW is a cysteine proteinase with a detailed role in the regulation and mechanism of T-cell cytolytic activity. The encoded CTSW is linked to the membrane inside the endoplasmic reticulum of natural killer and cytotoxic T-cells. CTSW expression is up-regulated by interleukin-2.

KLF4 is a transcription factor that performs as both an activator and repressor. KLF4 is expressed mainly in erythroid tissues and found mostly in gut. KLF4 is takes part in the differentiation of epithelial cells in addition to skeletal and kidney development.

Kallikreins are a subgroup of serine proteases having various physiological functions. Numerous kallikreins are involved in carcinogenesis. Kallikrein-11 (KLK11) which is a multifunctional protease is 1 of the 15 kallikrein subfamily members found in a cluster on chromosome 19. KLK11 cleaves synthetic peptides after arginine but not lysine residues.

Carcinoembryonic antigen (CEA) is a glycoprotein present in fetal digestive-tract tissues; it’s involved in cell adhesion. The production of CEA stops before birth. CEA is called tumor marker since its elevated levels are found in the serum from individuals with colorectal, gastric, pancreatic, lung and breast carcinomas and in heavy smokers.
There are also benign conditions that elevate CEA levels such as smoking, infection, inflammatory bowel disease, pancreatitis, cirrhosis of the liver, and some benign tumors (in the equivalent organs which have cancers with elevated CEA). Typically, higher levels of CEA are found in men, smokers, and older individuals.
The presence of CEA assists in screening, in evaluating recurrent or disseminated disease, and in determining the success of surgical removal of malignant tumors.
CEA levels can be used as indicators of treatment success. The normal values range from 0.0 to 2.5 ng/ml of serum (from blood), in non-smokers, a greater amount than that may be suggestive of cancer. Levels above 20 ng/ml before treatment are associated with cancer which has already metastasized. Benign conditions do not usually cause a CEA increase over 10 ng/ml.
The high levels of CEA should return to normal after successful therapy, however if during follow up there’s an elevation in CEA levels it indicates a recurrence of tumor.
Carcinoembryonic antigen family belongs to the immunoglobulin superfamily; it consists of 29 genes, 18 of which are normally expressed.

Resistin, a product of the RSTN gene, is a peptide hormone belonging to the class of cysteine-rich secreted proteins (monomeric peptide contains 11 cysteine residues) referred to as the RELM family, and is also described as ADSF (Adipose Tissue-Specific Secretory Factor) or FIZZ3 (Found in Inflammatory Zone 3). Mouse resistin is expressed as a 114 amino acid prepeptide; its hydrofobic Nterminal 20 amino acid signal peptide is cleaved before its secretion. Mouse resistin circulates in blood as a homodimeric protein consisting of two 94 amino acid polypeptides, which are disulfide-linked via Cys26.
Resistin may be an important link between obesity. Mouse resistin, specifically produced and secreted by adipocyte, acts on skeletal muscle myocytes, hepatocytes and adipocytes themselves so that it reduces their sensitivity. Steppan et al. have suggested that resistin suppressed the ability to stimulate glucose uptake. They have also suggested that resistin was present at elevated levels in blood of obese mice, and was down regulated by fasting and by antidiabetic drugs. Way et al., on the other hand, have found that resistin expression is severely suppressed in obesity.
Other studies have shown that mouse resistin increases during the differentiation of adipocytes, but it also seems to inhibit adipogenesis. In contrast, the human adipogenic differentiation is likely to be associated with a down regulation of resistin gene expression.

Activins are homodimers or heterodimers of the different β subunit isoforms, part of the TGFβ family. Mature Activin A has two 116 amino acids residues βA subunits (βA-βA). Activin displays an extensive variety of biological activities, including mesoderm induction, neural cell differentiation, bone remodelling, haematopoiesis, and reproductive physiology. Activins takes part in the production and regulation of hormones such as FSH, LH, GnRH and ACTH. Cells that are identified to express Activin A include fibroblasts, endothelial cells, hepatocytes, vascular smooth muscle cells, macrophages, keratinocytes, osteoclasts, bone marrow monocytes, prostatic epithelium, neurons, chondrocytes, osteoblasts, Leydig cells, Sertoli cells, and ovarian granulosa cells.

The cytokine Macrophage migration inhibitory factor (MIF) has been identified to be secreted by the pituitary gland and the monocyte/macrophage and to play an important role in endotoxic shock. MIF has the unique property of being released from macrophages and T cells in response to physiological concentrations of glucocorticoids. The secretion of MIF is tightly regulated and decreases at high, anti-inflammatory steroid concentration.

Syntaxin 4 (STX4) is a member of the syntaxin/epimorphin family of proteins. The Syntaxin family is cellular receptors for transport vesicles which participate in exocytosis in neutrophils. Syntaxin 4 is vital for normal regulation of glucose metabolism uptake in skeletal muscle and decline in STX4 protein levels lead to reduction of whole-body hormone-stimulated glucose metabolism. STX4 is expressed in neutrophils and neutrophil-differentiated HL-60 cells. The STX4 expression in neutrophils increases with differentiation.