Previous studies have identified several predictive biomarkers for ICIs treatment in mUC, including programmed death-ligand 1 (PD-L1) expression [4], CD8+ T cell [5, 6], tumor mutational burden (TMB) [7, 8], microsatellite instability (MSI) [5], and tumor-infiltrating lymphocytes (TILs) [9, 10]. The gene discussed is CD8A; the disease is neoplasm.