IDO1 and glioblastoma: Thus, in LGG, we found a significant correlation between LIGHT and immunological checkpoint proteins such as IDO1, CTLA-4, PD-1, PD-L1, and TIM-3 (Figure 7A, C, , E), whereas in GBM, we found a significant correlation between PD-1, PD-L1, CTLA-4, and B7-H3 (Figures 7B, D, , F).