While translocations involving the Ig genes in B cell lymphomas and off-target hypermutational activity of AID in other genome regions have been found in several other cancer types (e.g., gastric, liver, breast, ovarian, lung, and T cell lymphomas), AID-specific mutational patterns are clearly distinguishable from the APOBEC3B/A signature patterns [9, 10]. Here, APOBEC3B is linked to cancer.