APOBEC3B and cancer: An APOBEC3A-APOBEC3B fusion transcript may be produced due to a germline deletion polymorphism, which results in the complete loss of the coding part of the APOBEC3B gene and abolishes APOBEC3B gene expression; this deletion polymorphism produces a fusion product of the APOBEC3A gene with the 3′-UTR of APOBEC3B gene, and it has been associated with an increased risk of several types of cancer [7, 17].