Extended Data Fig. 2: Tetranucleotide context suggests a role for the A3A enzyme in generating omikli and A3B in kataegis mutations.

a, c, Ratios of the YTCA (A3A-like) and RTCA (A3B-like) mutation frequencies suggest differential mutagenic activity of A3A versus A3B enzymes in cancer samples. The C>T and the C>G changes in the two A3 contexts are shown in a pan-cancer analysis (panel a) and broken down by cancer type (panel c). At least 100 TCW mutations of a certain type across all tumor samples in a tissue were required to perform analyses on that tissue (number of mutations in brackets). Error bars are the bootstrap 95% C.I. of the ratio. KICH and THCA cancer types are not shown due to low overall number of A3-context mutations. b, Across multiple cancer types, omikli shows a tendency towards A3A-like, lower RTCA/YTCA-ratios than does kataegis. Difference tested by Fisher’s exact test (per tumor type), two-tailed; p-values were adjusted for multiple testing. Dashed line is FDR=20%. Lower odds ratios (<1) denote relative enrichment of YTCA (A3A-like) mutations in omikli compared to kataegis; see schematic above plot.