In the tumor site, MDSCs functions are strongly controlled by several soluble factors, such as IL-6, IL-10, TGF-β, CCR2, VEGF secreted by GB cells and immune cells, leading to the modulation of molecular pathways mediated by Janus tyrosine kinase (JAK) and signal transducer and activator of transcription 1, 3 and 6 (STAT1; STAT3; STAT6). This evidence concerns the gene STAT1 and neoplasm.