Answer:
Methylation
Step-by-step explanation:
The gene regulation is the important phenomena for the proper physical expression and metabolic function of the body. The gene may gets activate or inactivate depending upon the type of modification.
The acetylation modification increases the expression of gene. The methylation modification is done by the enzyme methyl transferase. The metylation at specific lysine residues result in the decrease or off gene expression.
Thus, the answer is methylation.