Resistin-like molecule-α (RELM-α) is a member of the RELM-family of secreted proteins containing C-terminal cysteines. The RELM-family consists of resistin (FIZZ3), RELM-α (FIZZ1), RELM-β (FIZZ2), and RELM-γ (FIZZ4). RELM-α is secreted by peripheral blood granulocytes, bone marrow, spleen, intestine, and lung. RELM-α functions to promote and regulate promyelocytic differentiation, in addition to regulating nutrient-associated insulin sensitivity in the intestinal tract. Rodents secrete all four RELM-family members, whereas resistin and RELM-β are the only RELM-family members found in humans.