The TNFA gene is significantly associated with the regulation of innate and adaptive immune responses. Polymorphism of TNFA gene is known to cause acute motor axonal neuropathy. The cytokine release and gene action is associated with epithelial cells, myeloid cells, endothelial, as well as tumor cells. Tumor cells are known to release TNFA, specifically in response to chemotherapy.
Transforming growth factor-α (TGF-α), is a 5.5 kDa polypeptide containing 50 amino acids in its mature form. It was originally identified as an agent that reversibly confers a transformed phenotype upon normal non-neoplastic cells, such as normal rat kidney fibroblasts. This activity requires the presence of transforming growth factor-β (TGF-β), which potentiates the action of TGF-α via a separate receptor. TGF-α is synthesized by monocytes, keratinocytes and many tissues and tumors. Mice genetically engineered to be lacking TGF-α expression showed no abnormalities except for the detection of a "wavy" hair coat. TGF-α exerts its action through the EGF receptor.