The inhibition of JAK ensures the inhibition of receptors; therefore, the subsequent biological effects, from a greater number of cytokines, are variably involved in the pathogenesis of pruritus, not only IL13 and IL4 but also IL31, IL2, IL8, IL25, IL33, IFNγ and thymic stromal lymphoprotein (TSLP) [21,24,25]. This evidence concerns the gene IL31 and Pruritus.