The skin actively interfaces with the environment and is the first-line of defense from all external factors. In mammals, the skin is an organ of the ‘integumentary system’ which is made up of multiple layers of ectodermal tissue that guards underlying muscles, bones, ligaments and internal organs. The skin specifically plays a key role in protecting the body against threatening pathogens and excessive water loss. The skin’s other functions include insulation, temperature regulation, sensation (i.e. feeling), and the production of vitamin D folates. Severely damaged skin may heal by forming scar tissue. These scars are sometimes discolored and de-pigmented.