Study: how genes cause illness

In a joint study, published January 20 in Nature Biotechnology and discussed in The New York Times, researchers from the Johns Hopkins School of Medicine and the Karolinska Institutet in Sweden found that genes and their regulatory "tags" conspire to promote rheumatoid arthritis, an immune disorder affecting roughly 1.5 million American adults.

Andrew Feinberg, King Fahd Professor of Molecular Medicine at Johns Hopkins and a lead author of the study, reports that the research team found hundreds of chemical tags but only four that seemed truly related to the disease. More from The New York Times:

It was much more complicated than just studying genes themselves. Researchers know a gene will remain stable, but the chemical tags that turn the genes on and off are not so reliable. Their presence can be affected by the environment or medications or even the activity of other, distant genes. They can be a consequence of a disease or set off a disease.