Confluent monolayers of human adipose stromal cells were cultured for 24 h in the absence (control) or presence of forskolin (25 μM) (cAMP), PGE2 or PGF2α (1μM each) and aromatase activity was assay by the incorporation of tritium from [3H]androstenedione into water. Modified from Y. Zhao, V.R. Agarwal, C.R. Mendelson, E.R. Simpson. Estrogen biosynthesis proximal to a breast tumor is stimulated by PGE2 via cyclic AMP, leading to activation of promoter II of the CYP19 (aromatase) gene, Endocrinology 137 (1996) 5739-5742 [20], with permission. Copyright 2006, The Endocrine Society.