- A critical role of non-active site residues on cyclooxygenase helices 5 and 6 in the control of prostaglandin stereochemistry at carbon 15Valmsen, Karin; Boeglin, William E.; Järving, Reet; Järving, Ivar; Varvas, Külliki; Brash, Alan R.; Samel, NigulasThe journal of biological chemistry2007 / 38, p. 28157-28163 https://www.sciencedirect.com/science/article/pii/S0021925820587127