Since the development of the BT142 model, a few additional PDX models have successfully cultivated gliomas that not only harbor IDH1 mutations and loss of 1p/19q genes (21, 36) but also retained parental metabolic fingerprints, infiltrative growth patterns, I high (R)-2HG production characteristic of LGG tumors (37). This evidence concerns the gene IDH1 and central nervous system cancer.