IDH1 and glioblastoma: All 42 GBM cases were histologically and molecularly classified as WHO grade IV IDH-wild type; neither IDH1/2 mutations nor ATRX mutations were identified at the immunohistochemical and molecular levels; no evidence of 1p/19q co-deletion was found; p53 immunohistochemical overexpression was found in only seven cases (17%), but no TP53 mutation was molecularly identified.