Lubinski et al. Vol. 190, No. 11, December 6, 1999. Pages 1637-1646.

The authors regret that the last paragraph of the Results section (p. 1641) contained an inaccurate statement. The corrected statement follows.

Total hemolytic complement activity was undetectable in serum from C3 knockout mice; however, after reconstitution with human C3 in vitro, total hemolytic complement activity was restored to levels detected in complement intact animals. After injection of human C3 in vivo, C3 levels were restored to physiological levels as detected by ELISA.