EGFR and non-small cell lung carcinoma: Combination therapy in NSCLC cells harboring a T790M mutation both in vitro and in vivo showed (107) that gefitinib (EGFR/HER1 TKI) used in combination with antimetabolites, either fluorouracil (5FU) or pemetrexed, had an antagonistic growth inhibitory effect in vitro.