DOT1L-induced H3K79 methylation is increased in DNMT3A-mutant human AML. Relative level of (A) unmethylated H3K79, (B) monomethylated H3K79, and (C) dimethylated H3K79 measured by mass spectrometry in 3 AML cell lines (KG1, THP1, and OCI AML3). Data are from a single biological replicate and 3 to 4 technical replicates. Error bars show standard deviation. P value was determined using unpaired 2-way Student t test. **P < .01; *P < .05. ns, not statistically significant.