ERBB3 and neoplasm: Based on data indicating HER2 and HER3 mutations are associated with efficacy of immune checkpoint inhibitors [39], a patient with metastatic urothelial carcinoma (mUC) was treated with anti-PD-1 antibodies and paclitaxel even though the tumor was PD-1 negative but contained an in-frame insertion of HER2 and HER3 amplification [40].