When considering mutation signatures (in SBS2, SBS13) in tumours expressing high levels of the cytidine deaminases APOBEC3A/APOBEC3B (apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like 3B and 3A) [23,24], it would be expected that UNG2 would influence the mutation spectrum. This evidence concerns the gene UNG and neoplasm.