Cytokine receptors are cell surface proteins which recognize specific cytokines as ligands. After binding their respective ligand, cytokine receptors undergo conformational changes that permit the cytoplasmic tail to initiate an intracellular signaling cascade. In most cases post-receptor intracellular signaling results in promotion or inhibition of transcription factors. However, some cytokine receptors have been termed decoy receptors. These receptors, such as IL-1 receptor type II, do not have cytoplasmic tails, therefore, intracellular signaling does not occur after IL-1 binding with IL-IRII. It appears that decoy receptors and soluble receptors (cytokine receptors released from cell surfaces) act as natural inhibitors of the immune response in order to keep inflammation from spreading unchecked.