The genes encoding sericin proteins have been sequenced. It consists mainly of two proteins, fibroin and sericin. The very thin fibers resulting from this process are covered with sericin, a special protein. Another variation under research is a silk-derived sericin hydrogel dressing. Sericin has also been used in medicine and cosmetics. Sericin is composed of 18 different amino acids, of which 32% is serine. Sericin is a protein created by "Bombyx mori" (silkworms) in the production of silk.