In addition, erlotinib has also been used in combination with gemcitabine for the clinical treatment of pancreatic cancer.78 The EGFR L858R/T790M dual mutation is the major cause of treatment failure (>50%) after taking the first generation of EGFR inhibitors.79 The second-generation irreversible EGFR-TKIs afatinib and dacomitinib are designed to conquer the T790M mutation.80,81 They can covalently bind to the ATP-binding pocket of EGFR and show stronger pharmacological activity than gefitinib. The gene discussed is EGFR; the disease is pancreatic neoplasm.