Aryl hydrocarbon receptor repressor

And as Leo mentioned, epigenetics are important because environmental exposures can leave epigenetic modifications in specific parts of the genome and they can affect potentially whether genes are on and off.

And one of the best studied examples is smoking, which leads to one of the strongest epigenetic signatures in AHRR.

gene that is losing methylation in smokers.

And just to put it a little bit more in context, disruption of DNA methylation in specific cases are linked to changes of whether genes are on and off, and this can lead to disease.