CgBTG1 is a B-cell translocation gene 1 homologue identified in Crassostrea gigas. CgBTG1 could prompt the apoptosis in oyster hemocytes and vertebrate cancer cells. CgBTG1 possessed an analogous function of angiogenesis in adductor muscle of oyster. CgBTG1 exhibited multiple functions in immune response of C. gigas.