To further identify the key regulator that promoting Trastuzumab resistance in GC, we generated two Trastuzumab‐resistant GC cell lines by subjecting HER-2 positive parental cell lines N87 and SNU-216 to long-term Trastuzumab treatment, naming them N87/Tr and SNU-216/Tr respectively. Here, ERBB2 is linked to gastric cancer.