In conclusion, based on known predictors, in HER2 positive metastatic GC, results from trials of trastuzumab deruxtecan, and similarly, margetuximab, in combination with checkpoint inhibitors should evaluated in the light of results from ongoing phase III KEYNOTE-811 trial (NCT03615326) that is focusing on trastuzumab and pembrolizumab combination, and then phase II INTEGA trial, exploring the combination of nivolumab and trastuzumab or chemotherapy plus ipilimumab (AIO STO 0217). This evidence concerns the gene ERBB2 and gastric cancer.