A family of resistin-like molecules (RELMs) has been identified in rodents and humans. RELM alpha belongs to a unique family of tissue-specific cytokines termed FIZZ (found in inflammatory zone) and RELM. The three known members of this family, Resistin, RELM alpha and RELM beta are 85-94 amino acid secreted proteins sharing a conserved C-terminal domain. RELM alpha and Resistin are secreted exclusively by adipocytes while RELM beta is expressed in the epithelium of the colon and small bowel. The RELMs together with resistin comprise a class of tissue-specific signaling molecules. The physiological role and molecular targets of RELM alpha are still unknown.
