CircUHRF1, secreted extracellularly by HCC cells, upregulates the expression of T cell immunoglobulin and mucin domain 3 (Tim-3) and inhibits the secretion of IFN-γ and TNF-α derived from NK cells, thereby inducing immunosuppression through NK cell dysfunction [34]. Here, HAVCR2 is linked to hepatocellular carcinoma.