MSI1 and glioblastoma: Interestingly, another recent study of ours that revealed that MSI1 promoted GBM tumorigenesis via upregulation of macrophage inhibitory factor 1 (MIF1) and M2 polarization [47] may provide another implication for the potential application of virus-free gene therapy based on blocking M1/M2 polarization of tumor-associated macrophages (TAMs) [48].