TROPICS-02 is an open-label, randomized, prospective, multicenter, phase III study evaluating the efficacy of sacituzumab govitecan (SG) compared to treatment of physician’s choice (TPC) in patients with locally advanced/metastatic, hormone receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer after failure of at least two—but no more than four—prior chemotherapy regimens for metastatic disease.3 The gene discussed is ERBB2; the disease is breast cancer.