An overwhelming excess of somatic mutations in APOBEC1 and APOBEC3A/B/G mutable motifs (Table 2) is likely to be due to the known excess of mutations in dipyrimidine dinucleotides (for example, TC) in skin cutaneous melanoma caused by mutagenic UV photoproducts [40]. The gene discussed is APOBEC1; the disease is cutaneous melanoma.