Indeed, metabolic profiling studies have demonstrated that cancer cells expressing IDH1 R132H, the most frequently-found mutation in IDH1 converting arginine residue 132 to histidine, accumulate extraordinarily high concentrations of 2HG (>10 mmol/L), which is in sharp contrast with the normal cellular concentration of αKG (~0.4 mmol/L). Here, IDH1 is linked to cancer.