The toxicity of T‐DXd remains an important issue; interstitial lung disease is presented by 26% of T‐DXd users [15], despite the recent approval (by the U.S. Food and Drug Administration) of T‐DXd for patients with unresectable or metastatic HER2‐mutated NSCLC. The gene discussed is ERBB2; the disease is non-small cell lung carcinoma.