In comparison to Singapore, UK skin shares multiple features with keratinocyte cancer, including a high mutational burden, a predominant UV mutational signature, increased CNA and increased selection of mutant TP53. This work supports previous studies suggesting that UV acts to promote carcinogenesis not only as a mutagen but also by promoting the expansion of preexisting TP53 mutant clones38, particularly of mutants that provide an advantage in UV-exposed skin, such as TP53R248W (ref. 26). The gene discussed is TP53; the disease is keratinocyte carcinoma.