As you know, I believe genes have been blamed for all sorts of medical calamities patients face when, in fact, their expression is what really counts. Turns out that epigenomes -- the regulators of your genetic expression -- may have far more to do with your health than genes.

Moreover, mapping the epigenome – a brand new world that's much more complex than the genomic one – may help physicians better predict, diagnose and treat illness.

Experts believe epigenomes can be passed through generations, which may explain why the diet of your grandmother could play a part in your increased risk of diabetes, but they can also change based on one's environment too.

Mapping out the structure of epigenomes won't be a snap, however, as they can change over time and differ in every major kind of cell, of which there are at least 200. It's time-consuming but certainly doable.

Wired August 16, 2005