HBP1 and glioma: In another study by the same authors found glioma exosomal miR-29a/miR-92a could also mediate the formation of immunosuppressive microenvironment via enhancing the proliferation and differentiation of functional MDSCs by targeting high-mobility group box transcription factor 1 (Hbp1) and protein kinase cAMP-dependent type I regulatory subunit alpha (Prkar1a), respectively [73].