Since the favorable results of single-agent SG established in the phase 2 TROPHY-U-01 (NCT03547973) trial and phase 3 TROPiCS-02 (NCT03901339) trial, the FDA has granted fast-track approval to SG for patients with locally advanced/metastatic urothelial carcinoma and unresectable locally advanced/metastatic hormone receptor-positive, HER2-negative BC (Tagawa et al., 2021; Rugo et al., 2022b). The gene discussed is ERBB2; the disease is breast cancer.