EGFR and small cell lung carcinoma: Comprehensive tumor tissue and plasma analyses of patients who progressed under osimertinib treatment revealed insights into various mechanisms of resistance, including novel EGFR resistance mutations [6,7,8,9,10,11,12], EGFR amplification [13,14], the activation of bypass pathways via ERBB2 amplification [15,16], MET amplification [7,13,15,16,17,18], RAS mutations [7,13,16,19], BRAF mutations [7,17,20], PIK3CA mutations [7,13], CDK4/CDK6/CDKN2A alterations [21], and transformation into small-cell lung cancer [7,22,23,24].