PDCD1 and neoplasm: As regards individual ICPMLs, the following have been reported to be associated with tumor cell EMT: PD-1 [54,55] PD-L1 [54,55,56,57], PD-L2 [54,55], B7-H3 [55], B7-H4 [43,58], CTLA-4 [54,55], OX40 [54], CD47 [59,60,61], CD137 ligand [62], CD155 [44], FGL1 [46], T-cell immunoglobulin and mucin-domain containing-3 (TIM-3) [55,63] and B- and T-lymphocyte attenuator (BTLA, CD272) [55].