Nat. Cell Biol. 13, 423–433 (2011); published online 20 March 2011; corrected after print 8 December 2014

In the version of this Article originally published online, incorrect values appearing in Supplementary Table S4 were used to generate Fig. 3a and to calculate the P and R values. The annotation between Exosome and HDL should have read 'R = 0.22*', the annotation between Exosome and LDL should have read 'R = 0.63**' and the annotation between HDL and LDL should have read 'R = 0.54**', where **P < 0.0001 and *P <0.001. The amended Fig. 3a is shown below. These errors have been corrected in the online versions of the Article, and in the Supplementary Information.