CD8A and non-small cell lung carcinoma: Hsa_circ_0136666 to regulate Treg cells activity via targeting the miR-497/PD-L1 axis in colorectal cancer [117], and cancer cell-derived exosomes circUSP7 to inhibit CD8 + T cell secretion of IFN-γ, TNF-α, granzyme-b, and perforin by adsorbing miR-934 to up-regulate protein tyrosine phosphatase 2 (SH2)-containing Src homology region 2 (SH2) expression in non-small cell lung cancer [118].