Too much use of lysine especially as a supplement has been linked to stomach discomfort and diarrhoea. The exception to the rule is the DOT1 household, members of which methylate K79 within the globular region of histone H3 and that are structurally not associated to SET-area proteins 4 - 6 Latest work means that SET-area-containing proteins methylate a number of proteins along with histones (see later)