CD274 and neoplasm: The first strategy was reported by Zhang et al. [177] who showed that cyclophosphamide-loaded PD-1-presenting platelets, by releasing PD-1-modified cyclophosphamide-loaded PMPs, blocked the immunosuppressive effects of PD-L1 on tumour cells, depleted regulatory T cells (Tregs), and promoted the appearance of CD8+ lymphocytes in the TME.