A meta-analysis of results from 12 RCTs investigated the association between patients with breast or gastric cancer treated with HER2-directed ADCs, including trastuzumab emtansine (T-DM1), trastuzumab deruxtecan (T-DXd), and trastuzumab duocarmazine, and the risk of developing ILD compared with controls [33–45]. This evidence concerns the gene ERBB2 and gastric cancer.