IDH1 and oligodendroglioma: Therefore, the relationship between the EMP3 hypermethylation and the favorable prognosis may not be due to the biological consequence of the EMP3 gene inactivation but more probably to the prevalence in oligodendrogliomas of both total 1p/19q codeletion and IDH1/IDH2 mutations and to their prognostic significance in these tumors [24, 37, 38].