NOTCH1 and glioma: PDGF‐D knockdown significantly downregulated NF‐κB p‐p65 and p‐I‐κB in the LN18 cells (p < 0.05) (Figure 4A), while overexpression of PDGF‐D increased the phosphorylation of both proteins (p < 0.05) (Figure 4B), indicating that PDGF‐D regulates NOTCH1 signaling in glioma cells through NF‐κB p‐p65.