ERBB2 and gastric cancer: Preclinical studies that investigated the inhibitory activity of various anti-HER2 drugs in HER2-positive gastric cancer cell lines (NCI-N87) found the IC50 of lapatinib, neratinib, and pyrotinib to be 10, 0.6, and 1.0 nmol/L, respectively (17, 18), suggesting that the antitumor activity of lapatinib in HER2-positive gastric cancer is evidently weaker than that of irreversible TKI pyrotinib.