CD274 and cancer: Several groups have demonstrated the potential role of cancer-derived EVs in suppressing the immune responses against different types of cancers mediated by NK and CD8+ T cells [84,85,86]; creating an immunosuppressive pro-tumor environment by expanding the TRegs population [87], stimulating M2 macrophage polarization [88] and dendritic cell tolerance [89,90]; or by suppressing CTL response through PD-L1 delivery [91].