In keeping with recent encouraging efficacy data in breast, gastric and non-small cell lung cancer (SCLC; NSCLC) [34, 35, 37], T-DXd was also evaluated in an open-label phase II trial, DESTINY-CRC01, enrolling patients with HER2 overexpressing mCRC or unresectable CRC, following progression after at least 2 lines of prior—including 30% who had received prior HER2 targeting treatment [49]. The gene discussed is ERBB2; the disease is small cell lung carcinoma.