CD4 and neoplasm: To assess whether this observed effect was dependent on VISTA, we added increasing concentrations (0, 0.2, 2, and 20 μg/mL) of VISTA-blocking antibody (clone 13F3) to CD4 T-cells co-cultured with mCB DNp53 MYC tumor cells at a 20:1 ratio (Figure 4c,d).