The BTLA (B- and T-lymphocyte attenuator) protein is induced on T cells following activation and acts as a ligand for the herpes virus entry mediator (HVEM), resulting in inhibition of T-cell responses and thereby playing an essential immunomodulatory role in different diseases including autoimmune diseases, cancer, transplantation and infection (41). The gene discussed is BTLA; the disease is autoimmune disease.