CD8A and liver cancer: EVs-derived circCCAR1 has been demonstrated to exacerbate CD8+ T cell dysfunction and resistance to anti-PD-1 therapy in liver cancer patients (133).Moreover, cancer-derived EVs-derived circUSP7 may induce CD8+ T cell dysfunction and anti-PD-1 resistance in NSCLC patients by regulating the miR-934/SHP2 axis (135).