CD80 and cancer: Other members of the B7 family include B7-H1 (PD-L1 or CD274), B7-DC (PD-L2), ICOS-L, B7-H3 and B7-H4, but only B7-H1 and B7-H4 have been indisputably shown to play a role in the immunoevasion of cancer cells [4].