Then, we classified 539 GBM cases of TCGA_GBM according to gene expression levels of PDGFA and PDGFRA into Subgroup 1 (PDGFAHigh/PDGFRAHigh, n = 25), Subgroup 2 (PDGFAHigh/PDGFRALow, n = 35), and Subgroup 3 (PDGFALow, n = 67) (Dataset 1). The gene discussed is PDGFA; the disease is glioblastoma.