BMP2 and glioblastoma: In PMN kidney biopsies from patients inside (Figure 3C–E) and outside (Figure S4, Supporting Information) of our scRNA‐seq cohort, immunofluorescence revealed elevated BMP2 expression around WT1 (podocyte nuclear marker) positive cells (Figure 3C), upregulated SMAD1 phosphorylation that colocalized with WT1 (Figure 3D), and augmented collagen IV levels in GBM compared with Ctrls (Figure 3E).