On page 6307 in the 28 June 2012 issue, the word “opsonization” at the end of the title is missing. The title should have read, “The complement receptor 2/factor H fusion protein TT30 protects paroxysmal nocturnal hemoglobinuria erythrocytes from complement-mediated hemolysis and C3 fragment opsonization.” The error has been corrected in the online version, which now differs from the print version.