C797S mutation in the same allele with the T790M mutationEGFR L792F/H/Y, G796S/R, L718Q, L798I, L692V and E709K mutations, and exon 20 insertionLoss of T790M mutationOncogenic gene fusionsMET, FGFR1, EGFR, ERBB2, MAPK1 amplificationHGF, EGF overexpressionIGFR upregulationPIK3CA, BRAF, KRAS, CDKN2A, ALK, KIT, RB1 mutationsHistologic transformation (EMT and SCLC). The gene discussed is KIT; the disease is small cell lung carcinoma.