PDCD1

PDCD1, programmed cell death protein 1, also known as PD1, CD279, and hSLE1, is encoded by the human PDCD1 gene, which is located on chromosome 2 at position q37.3.
The PDCD1 protein is an important immunosuppressive receptor, a member of the immunoglobulin superfamily, and is expressed mainly on activated T and B cells. Its mechanism of action involves binding to the ligands PD-L1 and PD-L2, which initiates programmed death of T cells, thereby inhibiting T cell activation and proliferation. PDCD1 plays an important role in maintaining peripheral T and B cell tolerance, and its enhanced signaling downregulates the response of activated T and B cells in peripheral tissues.
Abnormal expression of PDCD1 is associated with a variety of autoimmune diseases, infectious diseases and tumors, and is an important target for immunotherapy.