HLA-DRB1 and cancer: TrkB.T1 NSCs also exhibited downregulation of several MHC Class II genes, including HLA-DRB1, HLA-DRB5, HLA-DMA, HLA-DRA1, as well as the master transcriptional activator controlling expression of MHC Class II genes CITTA (Figs. 7c, d, Supplementary Data 6), highlighting the possibility that along with enhancing PDGF-driven signaling in vivo, the increased levels of TrkB.T1 observed in gliomas (Fig. 2) may also harbor a role in modulating antigen-specific immune responses that are often dysregulated cancer.