PDGFB and glioblastoma: While the data of Chen, Giotti, et al. indicated an IL1-β–independent mechanism for regulating BMDM infiltration in the Nf1-silenced tumors, data from The Cancer Genome Atlas (TCGA) showed levels of IL1B (and IL1A) were higher in human mesenchymal GBM, a finding consistent with elevated levels of Il1b in murine Nf1-silenced versus PDGFB-driven GBM models (8).