STAT3 and non-small cell lung carcinoma: Nevertheless, in vitro treatment of EGFR-mutated NSCLC cell lines with the first generation EGFR-TKIs erlotinib or gefitinib failed to impair pSTAT3 levels in the majority of tested cell lines, indicating that STAT3 is activated by mechanisms independent of mutant-EGFR in this context [45,51].