The<unk> s are a class of chemical compounds that are related chemically to vitamin A.<unk> s are used in medicine, primarily due to the way they regulate epithelial cell growth.<unk> s have many important and diverse functions throughout the body including roles in vision, regulation of cell proliferation and differentiation, growth of bone tissue, immune function, and activation of tumor suppressor genes.
Research is also being done into their ability to treat skin cancers. Currently 9-cis<unk>  acid may be used topically to help treat skin lesions from Kaposi's sarcoma.
Retinoid
Epoetin
Retinol
Beta-carotene
Adapalene
Carotene
Epoetin Alfa
Thiol