Nat. Biotechnol. 26, 509–517 (2008); published May, 2008; corrected after print 8 July 2008

In the version of this article initially published, Table 1 (pp. 510–511) contained two errors. In the entry for Agendia, the product Mammaprint was described as providing information on chemotherapy options for breast cancer patients. In fact Mammaprint is a prognostic test. In the entry for Genomic Health, the product Oncotype Dx was described as providing information on breast cancer recurrence. Oncotype DX also provides information on the response to chemotherapy. The error has been corrected in the HTML and PDF versions of the article.