From one of the articles in a freely-available Genome editing publication:
“Genomic studies frequently point to the important role that the full collection of epigenetic patterns in a cell nucleus has in complex diseases such as diabetes or schizophrenia, notes Tim Reddy, a genomics researcher also at Duke University. “In a lot of these cases, it really seems to be not a DNA mutation that impacts the protein sequence, but a change in how genes are regulated.”
Reddy says that he was surprised at the extent to which the expression of a target gene increased when a histone in an enhancer region was acetylated. “That result started to convince me that the acetylation of histones may be a direct cause of gene activation.”
Because of its simplicity and versatility, CRISPR–Cas9 opens up an opportunity. “If we want to target a region in the genome, we can have that targeting molecule here tomorrow for five dollars,” says Reddy.”
Reading this article and several of the publication’s other articles revealed the widespread belief that the goal of research should be to explain human conditions by explaining the actions of molecules. One problem caused by this preconception is that it leads to study designs and models that omit relevant etiologic evidence embedded in each of the subjects’ historical experiences.
http://www.nature.com/nature/journal/v528/n7580_supp/full/528S12a.html “Epigenetics: The genome unwrapped”