RELMγ belongs to a unique family of tissue-specific cytokines termed FIZZ (found in inflammatory zone) and RELM. The other three known members of this family; Resistin, RELMα, and RELMβ, are 85-94 amino acid secreted proteins sharing a conserved C-terminal domain characterized by 10 cysteine residues with a unique spacing motif of C-X11-C-X8-C-X-C-X3-C-X10-C-X-C-X-C-X9-C-C. RELMγ is most closely related to RELMα, but is distinctly secreted to bone marrow, spleen, lung, and in peripheral blood granulocytes. The physiological role of RELMγ may include the promotion or regulation of promyelocytic differentiation, although the specific molecular targets of RELMγ have not been identified. Recombinant muri