A family of tissue-specific resistin-like molecules

We have identified a family of resistin-like molecules (RELMs) in rodents and humans. Resistin is a hormone produced by fat cells. RELM alpha is a secreted protein that has a restricted tissue distribution with highest levels in adipose tissue. Another family member, RELM beta, is a secreted protein expressed only in the gastrointestinal tract, particularly the colon, in both mouse and human. RELM beta gene expression is highest in proliferative epithelial cells and is markedly increased in tumors, suggesting a role in intestinal proliferation. Resistin and the RELMs share a cysteine composition and other signature features. Thus, the RELMs together with resistin comprise a class of tissue-specific signaling molecules.