Fig. 1.

Somatic mutation rates and signatures in NPC. (A) Number of nonsilent somatic mutations in NPC tumors. (B) Trinucleotide contexts of somatic mutations occurring at cytosine nucleotides in NPC. The font sizes of the nucleotides at the 3′ and 5′ positions are proportional to their frequencies. (C) Mutational signatures are displayed according to 96 substitution classification defined by the substitution class and sequence context immediately before and after the mutated base (9). Vertical axis displays percentage of mutations attributed to a specific mutation type. The trinucleotide contexts of the mutated bases are shown on the x axis. (D) Expressions of APOBEC3A and APOBE3B evaluated by qRT-PCR in an additional 22 tumor pairs.