IDH1 and central nervous system cancer: Excess accumulation of d-2HG has been demonstrated in a subset of cases of glioma and AML with IDH1 or IDH2 mutations (Dang et al., 2009; Frezza et al., 2010; Gross et al., 2010; Ward et al., 2010; Andersson et al., 2011; Rakheja et al., 2011a; Choi et al., 2012).