A previous retrospective study by Tatematsu et al., which analyzed the incidence of minor-frequency preT790M using competitive allele-specific PCR in 153 surgically resected EGFR-mutated lung adenocarcinoma tissues, the incidence of preT790M was 29.4%, and T790M-MAF ranged from 0.13 to 2.65% (median MAF 0.20%) [36]. The gene discussed is EGFR; the disease is lung adenocarcinoma.