Analysis of variant allele frequencies (VAFs) of different driver gene mutations. The boxplot shows the median, 25th, and 75th percentiles, and minimum and maximum VAF observed across the entire cohort of 664 patients. VAFs were adjusted for local copy number. Boxes are colored according to the functional category assigned to each driver gene. Only mutations found in ≥20 patients were included. The black dashed line marks an allele frequency of 0.5, the expected VAF for a heterozygous variant present in all cells in the specimen. Insertions and deletions of ≥15 base pairs were excluded, because VAFs for larger variants were skewed, possibly because of amplification bias. VAFs for balanced translocations and inversions (ie, t(8;21), inv(16) and balanced translocations involving the KMT2A locus) were determined by interphase fluorescence in situ hybridization on ≥200 nuclei.