In fact, the oligomerization domain of C4BP provides the optimal distance between multiple protein-binding domains to maximize binding affinities to multimeric target receptors via multivalent interactions (37, 38) and, consequently, has also been exploited to increase the valency and performance of recombinant antibodies (39), soluble viral receptors (40), apoptosis-inducing peptides (41), or heteromultimeric FHR4-based immunoconjugates selectively activating the complement alternative pathway on tumor cells (42). Here, CFHR4 is linked to neoplasm.