So, our findings uncover that granulomatous stellate cells-derived PGD2 by activating DP2 receptors on eosinophils does stimulate production of anti-fibrogenic cysLTs, which endogenously down-regulates the hepatic fibrogenic process of S. mansoni granulomatous reaction — an in vivo protective function which demands caution in the future therapeutic attempts in targeting PGD2/DP2 in schistosomiasis. This evidence concerns the gene HPGDS and schistosomiasis.