CD274 and neoplasm: A recent study found that cis interaction also takes place between PD-1 and PD-L1 on the same surface of tumor cells or APCs.[27] By using protein-reconstituted membrane lipid bilayers and cell-based assays, the study demonstrated that cis interaction of PD-1 and PD-L1 on tumor cells or APC impedes the trans interaction of PD-L1 on tumor or APC cells with PD-1 on T cell, and thus represses the canonical PD-L1/PD-1 inhibitory signaling.