Indeed, a recent work suggest that tumor associated microglia (TAM) have been reported to be one source of IGF1.[16] Interestingly, subtype of neurons in the brain and hepatocytes in liver also express IGF1.[45, 46] Dissection the individual roles of these cellular sources in gliomagenesis and the self‐renewal of glioma TICs are currently undergoing. This evidence concerns the gene IGF1 and central nervous system cancer.