IGF1 and central nervous system cancer: Multiple immune-related signaling pathways, such as the phosphatidyl inositol-3-kinase/Akt pathway, IGF pathway, and programmed death-ligand 1 signaling, individually or collectively impact the TME of glioma (Kravchenko et al., 2015; Wang et al., 2016; Cai et al., 2018).