Díaz de Stahl et al. Vol. 197, No. 9, May 5, 2003. Pages 1183–1190.

The authors regret that there was a typographical error in the second complete sentence of the first paragraph on page 1184. The first CD35 should have been CD21. The corrected sentence appears below.

Mutant monoclonal IgM that has lost its ability to activate C cannot enhance, normal IgM cannot enhance in C-depleted mice or in Cr2−/− mice lacking CD21 and CD35 (17, 21), and monomeric IgM, which cannot activate C, does not enhance (22).