 The IL-19 gene is expressed in resting monocytes and B cells.It is up-regulated in monocytes following stimulation with granulocyte-macrophage colony-stimulating factor (GM-CSF), lipopolysaccharide, or Pam3CSK4.IL-19 increases the production of Th2 cytokines in T-lymphocytes and induces expression of IL-10 in monocytes.