While activating EGFR mutations have been known as predictors for response to anti-EGFR therapy in lung cancer, STAT3 activation was recently suggested as a potential predictive marker for resistance to anti-EGFR therapies in patients with mCRC and NSCLC, given the correlation between the activation of STAT3 and resistance of cells to anti-EGFR therapy [50,51]. The gene discussed is STAT3; the disease is lung carcinoma.