KRAS and lung adenocarcinoma: Furthermore, two patients with stage IV lung adenocarcinoma detected with EGFR exon 19 deletion and either concurrent KRAS K117N (n = 1) or concurrent de novo EGFR T790M (n = 1) achieved partial response with A+T regimen, with PFS of > 16.0 months and 10.3 months, respectively.