We do not think that the numbers of subunits we found in the PLY prepore and pore are at all unexpected. Tilley et al. (Cell, 2005) reported 31 ± 3 monomers in the PLY prepore, and two classes with 38 or 44 monomers in the PLY pore, in excellent overall agreement with our findings. Both the prepore and pore of Tilley et al. were in liposomes, so there can be no question that the number of subunits in our detergent-solubilized PLY pores is artefactual.