Notably, the frequency of circulating MDSCs is considered a negative prognostic indicator for patients receiving CTLA-4, PD-1, or PD-L1 targeted ICB therapy (177) Since, increased infiltration of MDSCs in cancer tissues is associated with resistance to various immunotherapies (178), one strategy to enhance the efficacy of ICB is to mitigate the immunosuppressive TME, with the application of inhibitors such as 1-methyl-L-tryptophan, which targets IDO, or the STAT3 antagonist JSI-124 to disrupt the immunosuppressive activity of MDSCs and optimize ICB efficacy (179). This evidence concerns the gene STAT3 and cancer.