Further analyses revealed the presence of a subgroup of BC patients with significantly decreased survival characterized by an exceptionally high accumulation of 2HG, reduced DNA methylation at the isocitrate dehydrogenase (IDH2) locus, increased IDH2 expression, and increased levels of S-adenosyl- methionine (SAM) and S-adenosylhomocysteine (SAH) [107]. Here, IDH2 is linked to breast cancer.