The upregulation of KCa3.1 expression is caused by HDAC2- and HDAC3-mediated epigenetic modifications as a pan-HDAC inhibitor vorinostat and selective inhibitors of HDAC2 and HDAC3 suppress the increase in transcriptional expression of KCa3.1 in the splenic CD4+ T cells in the DSS colitis model (Matsui et al., 2018; Fig. 1). Here, KCNN4 is linked to colitis.