What are the similarities between DNA methylation and histone acetylation?

There are several similarities between DNA methylation and histone acetylation. One similarity is that both are epigenetic modifications that occur in order to regulate gene expression. Another similarity is that both only occur in eukaryotic cells. Additionally, both processes will not cause any DNA sequence alteration. Another similarity is that chemical modifications due to enzymatic activities occur in both processes (methyl group donated by S-adenosine methionine in DNA methylation and adding acetyl group through acetyl coenzyme A donor in histone acetylation). Additionally, factors such as stress, the external environment, diet, and alcohol regulate both these processes. Lastly, both DNA methylation and histone acetylation occur within the nucleus.