In a phase I trial evaluating the effect of RC48 in HER2-overexpressing advanced or metastatic solid carcinoma patients (especially gastric cancer), RC48 was well tolerated and displayed encouraging antitumor activity in HER2-positive solid tumors with a 21.0% (12/57) objective response rate (ORR) and 49.1% (28/57) disease control rate (DCR). This evidence concerns the gene ERBB2 and gastric cancer.