CR2 encodes a membrane protein(complement C3d receptor 2),which functions as a receptor for Epstein-Barr virus (EBV) binding on B and T lymphocytes. Genetic variations in CR2 are associated with susceptibility to systemic lupus erythematosus type 9 (SLEB9). Alternatively spliced transcript variants encoding different isoforms have been found for CR2.蛋白別名為：CR2; C3DR; Complement receptor type 2; Cr2; Complement C3d receptor; Epstein-Barr virus receptor; EBV receptor; CD21;基因ID為：1380；蛋白質ID:P20023
