IDO1 and neoplasm: Figure 4 highlights the intricate interactions within the tumor microenvironment, driven by immunosuppressive mediators like arginase-1 and adenosine, which contribute to immune suppression and tumor progression in NSCLC. Representative pharmacologic interventions targeting TAMs and the immunosuppressive TME, including CSF1R blockade, TGF-β inhibition, and IDO1 pathway modulation, are summarized in Table 3.