AICDA and cancer: In addition to AID, its APOBEC relatives, the APOBEC3 sub-branch of enzymes (A3A, A3B, A3H), which have antiviral properties, are also a significant source of genome damage and mutations implicated in many types of cancers, such as breast, ovarian, and lung cancers, as the driving mutation and cancer progression associated signatures (68, 97–108).