Figure 3.

Primary resistance to immune checkpoint inhibitors (ICIs) in hepatocellular carcinoma (HCC). Factors of primary resistance can be divided into tumor cell intrinsic factors and tumor cell extrinsic factors. The former includes low or absent immune checkpoint expression, absence of neoantigens, dysfunction of antigen presentation, and mutations of genes or pathways, while the latter includes immunosuppressive cells and molecules and HCC-derived exosomes. This figure was reprinted with permission from reference [49]. Appropriate copyright permission was obtained.