EXaCT-1 analytical sensitivity and power analysis. (a) Power analysis shows that at a VAF threshold of 10–12% VAF, at least 28× total coverage is needed (P⩽0.05) for avoiding false-negative results if no mutation is present (0 reads). (b) Analytical sensitivity for low VAF detection for selected mutations. Synthetic mixed samples were generated from mutation-positive cell lines diluted into HapMap DNA with mixed proportion as determined by Ion Torrent AmpliSeq Cancer Hot Spot assay (EGFR, KRAS, BRAF and JAK2) (a) and by digital droplet PCR (HER2 copy number). (c) With proportions ranging between 50 and 2%. Experiments were performed in triplicate. The threshold of EXaCT-1 for detecting variants at low allele frequency was established at 10%.