Keratin Keratin Keratin () is one of a family of fibrous structural proteins. It is the key structural material making up hair, horns, claws, hooves, and the outer layer of human skin. Keratin is also the protein that protects epithelial cells from damage or stress. Keratin is extremely insoluble in water and organic solvents. Keratin monomers assemble into bundles to form intermediate filaments, which are tough and form strong unmineralized epidermal appendages found in reptiles, birds, amphibians, and mammals. The only other biological matter known to approximate the toughness of keratinized tissue is chitin. Keratin derives from Greek ' from '
The Name of this Book is Secret the back of his neck that is mentioned earlier in the book. They own a spa called "The Midnight Sun," which is run by alchemists whose mission is to search for secrets to everlasting life. As hinted several times in the book, Ms. Mauvais and Dr. L are much older than they look; they wear long gloves to hide their wrinkled skin, which only appears on their hands. They are described as dangerously beautiful. Dr. L. is tall, and he has silver hair that does not get messed, tanned skin, and the whitest teeth Cass had ever seen. He also