Fig. 3: Two acral melanomas with UV signature mutations accumulating after tumor initiation.

For both cases, the highest percentages of [C/T]C > T or CC > TT substitutions were observed in the MIS areas, which in case 48 (left panel) had an elevated mutation burden (5.7 vs. 1.1–1.3 mutations/megabase). The fractions were lower on the evolutionary trunks of both melanomas, suggesting limited or no exposure to UV radiation in the most recent common ancestors of both tumors. Source data are provided as a Source Data file.