We centred our investigation on the genes encoding the enzymes that convert 2-HG into α-KG9, D2HGDH and L2HGDH. We sequenced the entire coding region and intron/exon boundaries of D2HGDH and L2HGDH in an initial cohort of 69 DLBCLs and found six samples (8.7%) with four unique heterozygous mutations in D2HGDH (three missense, one truncating), but none in L2HGDH. To expand on this observation, we sequenced D2HGDH in an additional 80 DLBCL samples, and found another missense mutation in two independent tumours. Here, D2HGDH is linked to diffuse large B-cell lymphoma.