n. a family of regulator proteins, first of which is the B-Cell Lymphoma-2 (BCL-2) gene. These are genes whose proteins and protein products help regulate the balance between cell growth and death. Often implicated in programmed cell death, it is suspected to be involved in cancers of the breast, lung, prostate, and other lymphoma.

BCL-2: "In cases of follicular lymphoma, BCL-2 is one of the regulator proteins involved when chromosomal translocation occurs in chromosomes 14 and 18."