The effects of the major allergen recombinant Par j 1 (rPar j 1), of FF, of leptin, and of TGF-?1 on cell proliferation, on leptin/leptin receptor expression and modulation (by clonogenic test, by RT-q-RT-PCR, by immunocytochemistry and by flow-cytometry), and on STAT-3 activation (assessing nuclear translocation by western blot analysis) were assessed.     ///    "In vitro, in human nasal epithelial cell line RPMI 2650, we aimed to determine whether allergen stimulation acts on leptin/leptin receptor pathway and how fluticasone furoate (FF) influences this pathway. "    ///    "In conclusion, FF and leptin itself are able to preserve nasal epithelial homeostasis restoring the leptin/leptin receptor pathway altered by rPar j 1 exposure.. "    ///    "We found that rPar j 1 and TGF-?1 significantly decreased cell proliferation and down-regulated the leptin/leptin receptor pathway, whereas FF and leptin reverted them, both alone and in combination. "    ///    Fluticasone furoate maintains epithelial homeostasis via leptin/leptin receptor pathway in nasal cells.. 