These tails are subject to several submit-translational covalent modifications, including acetylation, phosphorylation, ubiquitination, sumoylation and methylation (reviewed in 1 ). The exception to the rule is the DOT1 household, members of which methylate K79 in the globular area of histone H3 and which are structurally not associated to SET-domain proteins four - 6 Latest work suggests that SET-area-containing proteins methylate just a few proteins in addition to histones (see later)