IDO1 and hepatocellular carcinoma: Therefore, we investigated the possible role of our IReRS in the ICB therapy of HCC (Figure 6C) by evaluating the relationships of the six well known targets of immune checkpoint inhibitors (including TIM-3, IDO1, CTLA-4, PD-1, PD-L1, and PD-L2) to the IReRS and immune-related eRNAs.