CD274 and neoplasm: To shed light on the anti-tumor effects of these mAbs against three different ICs, in the absence of immune cells, we investigated on the intracellular pathways downstream PD-1, PD-L1 and CTLA-4 by analyzing with suitable commercial antibodies the lysates of tumor cells treated for 72 h with the indicated mAbs at a concentration of 200 nM.