,11,14,15,19 Clinical investigation of T-DXd is also ongoing in several other patient populations, including patients with HER2-low breast cancer, HER2-positive or mutated metastatic non-small-cell lung cancer, or HER2-expressing advanced colorectal cancer, and those with early disease, among others.20, 21, 22, 23, 24, 25, 26. The gene discussed is ERBB2; the disease is non-small cell lung carcinoma.