KDM4A and cancer: KDM4A regulates H3K36me3 demethylation, but it also reduces levels of H3K36me2 as well as H3K9me2 and H3K9me3, with a higher affinity for the latter residue.14 While the role of the H3K9me3 mark is not fully understood, it is thought to be important in cancer development and to regulate apoptosis, DNA repair, splicing, self-renewal and other biological effects.15 Experimental inhibitors of KDM4A activity have emerged that suggest a beneficial effect in some cancers.16