The article reports on the risks of the antifibrinolytic agent aprotinin. Topics discussed include the reasons behind the withdrawal of the drug from the market in October 2007, criticisms leveled against the Blood Conservation Using Antifibrinolytics in a Randomized Trial (BART) which prompted the drug's withdrawal from the market and the arguments presented by BART authors to defend their claims on the risks of using aprotinin. Also discussed is Canada's decision to reintroduce aprotinin.