PGE2 and PGI2, in particular, two major prostaglandin metabolites of the eicosanoid end-products from the COX-2 mediated branch of the arachidonate pathway, were significantly elevated in TSC2-deficient cells, in preclinical models of TSC/LAM, and in sera from women with LAM [10]. This evidence concerns the gene PTGS2 and lymphangioleiomyomatosis.