Mutated IDH1/2 catalyzes the synthesis of D2-HG from α-ketoglutarate, consuming NADPH [124,125] that will not be available for fatty acid synthesis by fatty-acid synthase (FASN) [126,127], a marker for poor prognosis in IDH-wild type gliomas [128,129]. The gene discussed is FASN; the disease is central nervous system cancer.