IL17A (Interleukin 17A), also referred to IL17 or CTLA8 (Cytotoxic T-lymphocyte-associated serine esterase 8), is a 17.5 kDa glycoprotein encoded in humans by the IL17A gene that is located at the chromosome 6p12.2. It is composed of 155 amino acids and belongs to the IL17 protein family (IL17A- IL17F), of which each monomer contains four highly conserved cysteine residues. IL17A is a proinflammatory cytokine released by CD4+ T cells (Th17 cells), CD8+ T cells (Tc17 cells), invariant natural killer T cells (iNKT cells), γδ T cells and innate lymphoid cells (ILCs). This cytokine functions in the regulation of activities of NF-kappaB and mitogen-activated protein kinases. Its high levels are associated with several chronic inflammatory diseases such as psoriasis, rheumatoid arthritis, and multiple sclerosis. TNF (Tumor necrosis factor), also known as Cachectin, TNF-alpha, TNFA, TNFSF2 (Tumor necrosis factor ligand superfamily member 2), TNLG1F or DIF, is a 25.6 kDa proinflammatory cytokine that can stimulate the acute phase reaction and cause cell death or apoptosis. It has 233 amino acids encoded by the gene located at the chromosome 6p21.33. This factor is a member of the tumor necrosis factor superfamily (TNFSF), which can regulate many biological processes, including cell proliferation and differentiation, apoptosis, coagulation and lipid metabolism. It is a type of cytotoxin chiefly produced by activated macrophages, though can be expressed by other cells as well. This cytokine is involved in systemic inflammation and implicated in tumor regression, cachexia, and septic shock. And TNF functions through binding its receptors TNFRSF1A and TNFRSF1B.