Cheng et al. highlighted the impact of osteosarcoma-derived exosomes in macrophage M2-type polarization mediated by Tim-3, along with their release of cytokines, particularly IL-10, TGF-β, and VEGF, facilitating increased cell migration, invasion, EMT, and lung metastasis (Cheng et al., 2021). Here, TGFB1 is linked to osteosarcoma.