Once adsorbed/inserted into the membrane, alpha defensins are believed to aggregate into pore forming structures. Based on vesicle leakage and dextran permeability experiments, Wimley et al. (1994) proposed a multimeric pore model consisting of 6-8 defensin dimers which come together to form a large pore with inner diameter of 2-2.5nm. More recently using solid-state NMR and artificial lipid bilayers, Zhang et al. (2010) provide evidence of a dimer pore model in which the polar top of the dimer lines an aqueous pore while the hydrophobic bottom faces the lipid chains. Regardless of the exact conformation, the resulting pores then allow the efflux of essential microbial cell components.