HLA-DRB1: Proteins and Enzymes

HLA-DRB1 is an HLA class II histocompatibility antigen. It is part of a heterodimer consisting of an alpha (DRA) and a beta chain (DRB) which are both anchored in the membrane. Class II molecules are constitutively expressed in professional APC's. HLA-II is an important immune system protein that plays a role in tumor antigen presentation, immune response, and immune surveillance. HLA-DRB1 presents antigenic peptides to HLA-DRB1-restricted CD4+ T-cells. Aberrant expression of HLA-II is closely related to the pathogenesis of tumors.