Multiple funding organizations and grants were incorrectly omitted from the Funding Statement. The Funding Statement should read: \"Funding was provided by NIH/NIAID grant AI13013 (to R.M.S.), The Rockefeller University Center for Clinical and Translational Science Grant Award Number ULTR000043 (to J.I.), NIH/NIAMS grant 1K99AR062595 (to J.I.), and by the Fundação para a Ciência e Tecnologia PhD scholarship SFRH/BD/41073/2007 (to I.M.). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.\"

**Competing Interests:**No competing interests declared.
