KMT2A and hematocrit: Based on an epigenetics study, Lu et al. showed that the increased protein levels of the trimethylation of histone H3 lysine 4 (H3K4me3) and Mixed lineage leukemia 1 (MLL1) in HT patients, which can be explained by the abnormal H3K4 trimethylation in lymphocytes and monocytes of thyroid tissue [197].