This study does not involve any particular diagnosis. The goal of this research study is to explore the effects of artificial sunlight (ultraviolet B radiation; UVB) on the skin of young adults versus geriatric adults. Sunlight exerts many effects on the body. There is evidence that in response to ultraviolet B radiation (UVB), which are the burning rays of sunlight, young adult skin responds differently than geriatric skin. In fact, researchers feel that this difference in how the skin reacts to UVB is why skin cancers are found in older skin. Researchers believe that a major difference between young adult and geriatric skin is that young skin has a lot of a protein called insulin-like growth factor-1 (IGF-1), whereas geriatric skin has very little. The current study will test how young adult versus geriatric skin responds to UVB, and if geriatric skin treated with an injection of small amount of IGF-1 drug will then act like young skin.