Recruitment of the C8 trimeric complex is mediated by the C8 beta chain (Monahan & Sodetz 1981). Binding enables C8 to undergo necessary conformational rearrangements that allow the C8 alpha chain to penetrate into the hydrophobic core of the lipid bilayer (Stecket et al. 1983, Weiland et al. 2014), firmly anchoring the C5b:C6:C7:C8 complex to the target cell membrane. A functional membrane pore can be formed by the C5b:C6:C7:C8 complex (Boyle et al. 1976, Tegla et al. 2011). These pores are small and unstable but can cause cell lysis if present in sufficient number (Martin et al. 1987). They also increase cytosolic free Ca2+ concentration and thereby stimulate signalling pathways (Koski et al. 1983, Niculescu & Rus 2001).