NF1 and central nervous system cancer: The polarization of GAMs to immunosuppressive M2 type is a representative tumorigenic process positively bound up with the grading and rapid recurrence of gliomas (Wang Q. et al., 2017; Sorensen et al., 2018), which was widely found in mesenchymal GBM cells and was related to NF1 loss (Wang Q. et al., 2017).