All patients were affected by advanced stage adenocarcinoma (surgically unresectable stage III or metastatic stage IV) harbouring a druggable EGFR mutation; most patients had a single metastatic site involved (29/48; 60%) and underwent treatment with a first- (Gefitinib) or second- (Afatinib) generation anti-EGFR TKI (Table 1). The gene discussed is EGFR; the disease is adenocarcinoma.