APOBEC3A and cancer: Analogous experiments have yet to be conducted with other cancer-associated APOBEC family members including A3A, APOBEC1, and AID but, given the processive nature of these enzymes68,69, the fact that most family members preferentially deaminate ssDNA substrates28,31,68, and the high prevelance of APOBEC signature mutations in the majority of human cancer types3,7,23,70, it is likely that the example detailed here will constitute the first of many studies on mutational synergies between A3B, related deaminase family members, and a wide variety of exogenous DNA mutagens and carcinogens.