Aberrant 5hmC levels in AML. (A) In AML cells, a broad range of 5hmC levels was detected at diagnosis when compared with healthy CD34-positive cells. (B) Aberrant 5hmC levels at diagnosis were restored to normal levels in remission. (C) For 5 AML patients, 5hmC levels were measured at diagnosis, remission, and relapse. The 5hmC levels were in 4 of 5 cases comparable at diagnosis and relapse. For unique patient number (UPN) 128, the 5hmC level at relapse was remarkably higher than at diagnosis due to an IDH1 mutation at diagnosis that was absent at relapse. Dashed lines indicate the range of 5hmC values measured in healthy BM and healthy PB.