Conflicts of interest: ML has been a consultant for Abgenomics, Allos, Amgen, Astellas Pharma, DermaGenoma, DermiPsor, Ethicon, Genentech, GlaxoSmithKline-Stiefel, HelixBioMedix, Janssen Ortho Biotech, LEO Pharmaceuticals, Novartis, Nycomed, Onset Therapeutics, Pfizer, and Valeant Pharmaceuticals. He has been a speaker for Glenmark Pharmaceuticals and Ranbaxy. He has been an investigator for Can-Fite BioPharma and Clinuvel. ARS is formerly of Novartis Pharmaceuticals Corporation and now is an employee of GlaxoSmithKline. JN is an employee and shareholder, Novartis Pharmaceuticals Corporation. EK is an employee and shareholder, Novartis Pharmaceuticals Corporation. CJG is an employee of invivodata, inc. (now ERT), which received funding from Novartis Pharmaceuticals Corporation to conduct this study. BES has served on advisory boards for Abbott, Amgen, Centocor, Novartis, Pfizer, and Leo. He has served as a consultant for Abbott, Amgen, Centocor, Maruho, Novartis, Pfizer, and Celegene. He has received honoraria from Abbott.