CXCR4 and bladder transitional cell carcinoma: Given that the CD8+ T cells are extremely active in BLCA cell communication, suggesting an important role in intercellular interactions, we further explored the ligand receptors in cell communication of CD8+ T cells according to the GPR risk score, and we found that CD8+ T cells in both GPR-high and GPR-low risk groups interacting with MIF-(CD74 + CXCR4) ligand–receptor relationships were extremely correlated (Figure 4h and i).