(B) The contributions of mutational signatures to individual tumors. Each bar represents a sample, and samples are ordered by the proportion of signature A found in them. The three mutational signatures are represented by the different colors shown in (A). For signature A, a significant number of mutations in a sample is defined as more than 100 substitutions in total or more than 25% of all mutations in that sample. Red or black triangles indicate samples harboring the PIK3CA c.1624G>A (p.Glu542Lys) or c.1633G>A (p.Glu545Lys) mutation, respectively.