Fig. 2.

Features of actionable mutations with low VAF. a Concordance between VAFs estimated from panels and dPCRs for low VAF variants. The Pearson correlation coefficient based on 59 actionable variants is 0.86. Variants with higher coverage (colors correspond to sequencing depths) tend to show higher correlation; also see Supplementary Data 4. b Differences in VAF distributions among EGFR mutations in eight refractory lung cancer samples harboring EGFR C797S. All samples had an activating mutation (EGFR exon19 non-frameshift (NFS) deletion or L858R) and two resistance mutations (EGFR T790M and C797S), with the latter occurring at lower VAF. Dotted lines indicate mutations belonging to the same sample. The P-values were calculated using the paired t-test. c, d Browser view of the case in which EGFR C797S occurred in cis with EGFR T790M (only a subset of the reads are shown). e An acquired EGFR C797S mutation is found after AZD9291 therapy. f Comparison of VAF of EGFR variants of lung cancer samples (n = 141) pre- and post-EGFR-TKI therapy (afatinib, erlotinib, or gefitinib). The P values were calculated using the Wilcoxon rank sum test