NPC1 and glioblastoma: Consistent with the global analysis (Supplementary Table S1), BMP4 treatment downregulated signatures related to cell cycling and neurodevelopmental/PN-associated GBM cell states, including the activity of the stemness transcription factor SOX2, neuronal progenitor cells (NPC1 and NPC2), oligodendrocyte precursor cells (OPC), and astrocyte-like cells (AC) (Figure 1K).