Four Johns Hopkins laureates won Nobel Prizes in Physics, including Riccardo Giacconi in 2002 and Bloomberg Distinguished Professor Adam Riess in 2011. Bloomberg Distinguished Professor Peter Agre was awarded the 2003 Nobel Prize in Chemistry (which he shared with Roderick MacKinnon) for his discovery of aquaporins. Bloomberg Distinguished Professor Carol Greider was awarded the 2009 Nobel Prize for Physiology or Medicine, along with Blackburn and Jack W. Szostak, for their discovery that telomeres are protected from progressive shortening by the enzyme telomerase.