In NUGC4 cell models, we evaluated the effect of crizotinib (50 mg/kg), since we have previously reported that 25 mg/kg and 50 mg/kg of crizotinib inhibited the progression of peritoneal carcinomatosis produced by NUGC4 cells 23, and that of brain tumors produced by EML4‐ALK‐positive A925L lung cancer cells 15, respectively. The gene discussed is ALK; the disease is brain neoplasm.