IDH1 and neoplasm: In 2017, TCGA further identified three subtypes of GBM, namely, classical, pro‐neural, and mesenchymal where they correlated intrinsic gene signature with tumor immune microenvironment.[14] In this study, they recruited patients with no IDH mutation as they showed better prognosis in previous studies[23] and established the relationship between treatment and phenotypic alterations with GBM subtypes in recurrent tumors.