Anaemia is a serious problem, not just for those with a lack of iron in their diet but for millions of patients with kidney disease, and for those undergoing cancer treatment. Anaemia in these cases results from the loss of a key protein called erythropoietin (EPO), which stimulates red blood cell production. The market is dominated by Amgen and Johnson & Johnson, whose sales of recombinant EPO replacement drugs (epoetins) totalled nearly US$10 B in 2006. However, threats are looming that may disrupt this dominance. Safety fears over the long-term use of epoetins, the impending introduction of biosimilars and the launch of newer and longer lasting treatments, such as Roche#8217;s CERA, will provide the biggest shake up in the market#8217;s 20-year history.