CTLA4 and urinary bladder carcinoma: Considering our original finding of a partial response of patients with bladder cancer to α-CTLA-4 monotherapy and the recent report of a noteworthy activity of α-PD-L1 antibody MDPDL3280A in patients with bladder cancer53, we reason that combination therapy represents a more effective approach, which is consistent with our observations of the high expression of PD-L1 on MB49 cells, upregulation of PD-1 induced by α-CTLA-4 treatment in both human and murine bladder tumour samples, and strong synergism of α-CTLA-4 and α-PD-1 in tumour rejection.