Zhang PF and his colleagues found that NK cell depletion and impaired function were caused by the HCC-derived exosome circUHRF1 through upregulation of TIM-3 expression, thereby inhibiting the production of IFN-γ and TNF-α by NK cells, and ultimately leading to rapid growth and spread of cancer cells [16, 42].Therefore, NK cells can be regarded as potential targets in the areas of HCC therapy. Here, TNF is linked to hepatocellular carcinoma.