Here, we demonstrate that Inositol Polyphosphate-5-Phosphatase F (INPP5F), one of the polyphosphoinositide phosphatases, is differentially expressed in GSCs from glioma patients, and is identified as an inhibitor of STAT3 signaling via interaction with STAT3 and inhibition of its phosphorylation. This evidence concerns the gene FIG4 and central nervous system cancer.