ERBB2 and non-small cell lung carcinoma: In a study of 65 NSCLC cell lines, the growth inhibitory potency of afatinib varied markedly; it was most potent in cell lines harbouring overexpressed wild-type, mutated or amplified EGFR or HER2 and much less potent in those expressing normal levels of EGFR or mutated BRAF, KRAS or NRAS (Pfeifer et al. 2010).