IDH1 and anaplastic oligodendroglioma: As a potential explanation for how redox homeostasis can be restored in IDH mutant cells, Hollinshead et al. found that human anaplastic oligodendroglioma cells expressing the IDH1-R132H mutant had increased expression of the enzyme proline 5-carboxylase reductase 1 (PYCR1), which is involved in proline biosynthesis [110].