Tackling new challenges and engaging in cognitive games can assist preserve the mind sharp and more immune to the influence of dieting. 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-area proteins 4 - 6 Latest work suggests that SET-domain-containing proteins methylate a few proteins along with histones (see later)