TNF and hepatocellular carcinoma: HCC cell-derived exosomes can transfer circUHRF1 into peripheral NK cells and inhibit its activity by sponging miR-449c-5p to achieve the high expression of downstream target gene T-cell immunoglobulin mucin 3 (TIM-3), thereby inhibiting the secretion of interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α) from NK cells, leading to impaired function and phenotypic exhaustion of NK cells to promote immune escape of HCC cells (78).