Nat. Biotechnol. 31, 195–201 (2013); published online 7 March 2013; corrected after print 30 April 2013

In the version of this article initially published, in Table 1, the number of health biotech firms, including those not backed by venture capital, in South Africa, was given as 78 in 2007. It should be 64 in 2010. The error has been corrected in the HTML and PDF versions of the article.