HOXD9 and oligodendroglioma: A study by Mamatjan et al. analyzed HOX gene overexpression and hypermethylation and proposed a seven HOX gene signature (HOXA4, HOXA7, HOXA10, HOXA13, HOXD3, HOXD9, and HOXD10) that was shown to be prognostic in IDH mutant astrocytoma and oligodendrogliomas [47].