HDAC1 and Henoch-Schoenlein purpura: In addition, other epigenetic modification enzymes, HDAC1, 2, and 4 SIRT1, LSD1, and KDM3A are decreased, whereas CREBBP, PCAF, SETD1A, MLL, STEDB1, and SUV39H2 are increased in IgA vasculitis, suggesting that these epigenetic modification enzymes might organize DNA and histone modifications in patients with IgA vasculitis and exacerbate inflammatory responses [143].