Melatonin induces dephosphorylation and nuclear import of histone deacetylase 4 (HDAC4) in cancer cells; melatonin exerts this effect through inactivation of Ca2+/calmodulin-dependent protein kinase II alpha (CaMKIIα), leading to the H3 acetylation on Bcl-2 promoter and subsequent reduction of Bcl-2 expression [117]. Here, HDAC4 is linked to cancer.