Moreover, both T-DM1 in HER2-overexpressed (IHC 3+) NSCLC and T-DXd in HER2-amplified NSCLC have shown an ORR of 20% and 24.5%, respectively, which is lower for T-DXd in HER2 mutant NSCLC [40,45]. The gene discussed is ERBB2; the disease is non-small cell lung carcinoma.