CD274 and urinary bladder cancer: Similar phenomenon has been found in bladder cancer, where the high expression of PD-L1 on circulating monocytes and TAMs in bladder cancer patients promotes T cell apoptosis and inhibits T cell proliferation, and this expression is further upregulated by IL-10 secreted by bladder cancer cells through STAT3 signaling pathway, ultimately establishing a cycle in TME leading to the reduction in cytotoxic T cells (53).