Blocking TSLP results in strong inhibition of the CCL2 -related eosinophilic pathway, as well as Th2- related cytokines (IL-4 and 13) and Th17 (212), all of which are involved in the pathogenesis of EGPA (16, 24, 44). Here, IL4 is linked to eosinophilic granulomatosis with polyangiitis.