IL1B and Peritoneal Fibrosis: Interestingly, recent data have shown that microsomal prostaglandin E synthase-1 (mPGES-1)-derived PGE2 plays a critical role in PD-associated peritoneal fibrosis through activation of the NLRP3 inflammasome [48], a cytosolic receptor that, once activated, induces the maturation of the proinflammatory cytokines IL-1 and IL-18 [49].