CD274 and urinary bladder cancer: As shown in Figures 5F–I, a high level of expression of the four CLRs is significantly correlated with the upregulation of a range of immune-checkpoint ligands and proteins in the microenvironment of the bladder in bladder cancer, and they can be divided into two subgroups: those mainly expressed on tumor cells, such as PD-L1 and PD-L2, and those mainly expressed on T cells, including PD-1, CTLA-4, TIM-3, LAG3, and TIGIT.