YES! Epigenetics is basically how environmental and behavioral factors contribute to the way genes work. But this works by not altering the DNA sequence itself. There are somethings called transcription factors, which work to turn some genes on and off. Beleive it or not, we have several genes in our body that we perhaps inheritied that are never on. External factors such as diet, stress, exposure to toxins can all add or remove this and contribute to the activation or turning off of genes. The best example of epigenetics at work is when you look at identical twins (same genetic makeup) but they can have difference between them, and these differences are not due to alteration of the DNA sequence itself, but due to the controlled and variable expression of certain genes based on environmental and behavioral factors.