A secondary point mutation in exon 20 of EGFR, which leads to substitution of methionine for threonine at position 790 (T790M), accounted for more than half of the cases with NSCLC who developed acquired resistance to the first-generation EGFR-TKIs (gefitinib and erlotinib) [1]. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.