Interleukin-22 interacts with its receptor, referred to as IL-22R, and instigates a series of reactions, leading to activation of various molecules, such as JAK-1, Tyk2, and others. One can identify molecules which mediate this interaction by measuring the activity of one or more of the molecules in the pathway, to identify agonists and antagonists. These, in turn, are useful therapeutic agents, where inappropriate expression of one of the activated molecules is at issue, and requires amelioration.