PDCD1 and neoplasm: In this line, treatment with miR-424 KO tumor-derived EVs induces the expansion of T cells against tumor antigens and increases the effectiveness of anti-PD-1/CTLA-4 antibodies, evidenced by the inhibition of tumor growth and metastasis, and the increase in median survival in a colorectal cancer model, since miR-424 is a negative regulator of the CD28-CD80/86 axis [157].