The skin is not only the body's largest organ but is widely considered to be the sentinel organ of the human body as it is often the first line of defense from environmental insults. Acting as both an environmental sensor and guardian, the skin responds to external cues and helps us adapt to our surroundings in many ways, such as tanning to adapt to repeated ultraviolet (UV) exposure. In order to better understand the molecular events that occur as the skin adapts to its environment, we need a deeper understanding of how the genes in the cells comprising the skin are regulated and how this regulation leads to changes in biological response. Regulation of messenger RNA (mRNA) ultimately results in changes in protein production, which is responsible for carrying out the physical and chemical reactions responsible for the skin's adaptation response. Each step in this cellular response is the subject of intense research. In fact, scientific sub-disciplines have developed around understanding each of these steps: genomics, proteomics and metabonomics. There are a myriad of applications for genomics in skin. Since capabilities, such as gene chips, provide fundamental molecular insights into skin cell biology that can be exploited for the development of new products, it is anticipated that genomics will continue to play an ever-increasing role in skin care.