Eligible patients aged 18 or over who qualified for pembrolizumab therapy based on FDA-approved indications were included: urothelial carcinoma having progressed during or following platinum-based chemotherapy; MSI-H or dMMR solid tumors; gastric or gastroesophageal junctio3n adenocarcinomas expressing PD-L1 (CPS ≥ 1) who had progressed on at least two prior lines of systemic chemotherapy, and, if appropriate, HER2 / neu-targeted therapy. Here, ERBB2 is linked to urothelial carcinoma.