Bypassing complement: evolutionary lessons and future implications
J. Clin. Invest. John P. Atkinson, et al. 116:1215 doi:10.1172/JCI28622 [Go to this article.]

Figure 1
Three pathways of complement activation. Deposition of clusters of C3b on a target is the primary goal. The alternative pathway also serves as a feedback loop such that C3b deposition can be amplified (shown by broken line).