Lack of activity of recombinant HIF prolyl hydroxylases (PHDs) on reported non-HIF substrates oleh Matthew E Cockman, Kerstin Lippl, Ya-Min Tian, Hamish B Pegg, William D Figg Jnr, Martine I Abboud, Raphael Heilig, Roman Fischer, Johanna Myllyharju, Christopher J Schofield, Peter J Ratcliffe