CD80 and cancer: Strikingly, tumors with a strong expression of F3 in cancer cells displayed high levels of the immune checkpoints CD274/PD-L1, PDCD1LG2/PD-L2 and CD80/B7-H1 in the tumor-infiltrating dendritic cells (DC) (median levels of 4.45 in high F3 vs. 0.10 in low F3; 4.01 in high F3 vs. 0 in low F3 and 4.78 in high F3 vs. 0 in low F3, respectively) (Figure 9).