Crizotinib is a first generation targeted drug. This drug is a first-generation targeted drug in the ALK inhibitor class, a dual blocker of the ALK and c-MET genes or their variants, and is mainly used in the treatment of non-small cell lung adenocarcinoma, which can effectively prolong the progression-free survival of patients. As a first-line therapeutic agent, this drug can extend the survival cycle of patients by 14 to 19 months, while obtaining longer disease control, but resistance will occur after 1 to 1.5 years of drug administration, which needs to be replaced by second- or third-generation targeted drugs such as erlotinib and ceritinib. Crizotinib during the drug will appear diarrhea, rash, liver transaminase elevation and other adverse reactions, it is recommended that you do the relevant tests, timely targeted treatment.