(1) protection against reactive oxygen species (ROS) by antioxidant molecules (such as glutathione) and detoxifying enzymes (such as catalase and superoxide dismutase); (2) DNA repair, particularly for double-strand breaks, that disappears at doses >0.5 Gy; and (3) elimination of genomically damaged cells by immune defenses and apoptosis at doses as low as a few mSv. The hormesis response is associated with increased lifespan, and decreased mutations, chromosome aberrations, neoplastic transformations, cancer, and congenital malformations (Kant, Chauhan, & Sharma, 2003).