IDO1 inhibitors, such as INCB024360, have garnered increasing attention,36 and subsequent studies have demonstrated that combining IDO1 inhibition with immune checkpoint inhibitors could significantly enhance therapeutic efficacy.37 One study found that dual inhibition of IDO-1 and TDO with PVZB3001 suppressed tumoral growth and decreased the KYN/TRP ratio.38 Building on these promising preclinical findings, clinical trials are now investigating the efficacy of IDO-1 inhibitors in GBM. This evidence concerns the gene IDO1 and glioblastoma.