Monokine with inflammatory, pyrogenic and chemokinetic properties. Circulates at high concentrations in the blood of healthy animals. Binding to a high-affinity receptor activates calcium release in neutrophils. It also inhibits colony formation of bone marrow myeloid immature progenitors. Expressed mainly in the liver, lung, and the thymus, although some expression has been detected in a wide variety of tissues except brain. By interleukin-4; in the bone marrow macrophage. Belongs to the intercrine beta (chemokine CC) family.