Fig. 1

CircRNAs play a vital role in regulating tumour immunity. a circRNAs are transported to immunocytes through exosomes and extracellular vesicles secreted by the tumour cell to regulate immune responses. b exogenous circRNAs entering tumor cells may activate RIG-1-mediated pathway and activate antitumour immunity. c circRNAs promote the expression of PD-L1 in tumour cells, inhibit the activation and proliferation of T cells, and induce T cell apoptosis. d circRNAs can inhibit the killing ability of NK cells through the circ-0000977/miR-153/HIF1α axis. e circRNAs can also upregulate target mRNAs and ULBP1 protein levels to enhance the cytotoxicity of NK cell and upregulate NK-mediated immune responses. The green arrow indicates stimulatory modification, and the red “T” symbol indicates inhibitory modification