To examine activated T-lymphocyte cytotoxicity against BIU-87 human bladder urothelial carcinoma cells following blockade of the B7-H4 signaling pathway in vitro, control and B7-H4 mAB-stimulated BIU-87 cells were mixed with the activated T lymphocytes at different ratios. Here, VTCN1 is linked to bladder transitional cell carcinoma.