Therefore, we previously conducted a study aimed to accurately detect preT790M and clarify the prevalence of preT790M in a larger cohort that was an EGFR-mutant subset within the Japan Molecular Epidemiology (JME) study cohort, and we reported that preT790M was detected in 298 (79.9%) of 373 EGFR-mutated NSCLC patients using the ultra-sensitive droplet digital polymerase chain reaction (ddPCR), the analytical sensitivity of which was approximately 0.001% [14]. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.