We studied the effect of EGCG on proliferation, apoptosis, and EGFR signaling (mTOR, MAPK38 and STAT3) in three NSCLC cell lines harboring an in-frame deletion of exon 19 (EGFRDel19), double mutations T790M/L858R (EGFRL858R/T790M), and wild-type EGFR. The gene discussed is STAT3; the disease is non-small cell lung carcinoma.