The fact that the investigated AMPs readily permeabilize DMPC/PG membranes both in the gel and fluid phase, but not DSPC/PG nor POPC/PG membranes, is noteworthy. It begs the question of how the ion-permeability of heterogeneous membranes are affected by these AMPs. Cellular and bacterial membranes are not comprised of a single population lipids, but typically display a large degree of heterogeneity both in lipid composition , and also in lateral organization of the lipids . Specifically, mismatch in lipid tail lengths or extension, and hence membrane thickness, has been shown to drive phase separation and formation of lipid rafts . We have also recently shown that addition of AMPs to these phase separated membranes promotes further separation and raft growth . We hypothesize that the presence of thinner membrane regions, as well as phase boundaries in heterogeneous membranes, might allow for AMP facilitated ion-permeabilization even in membranes containing significant fractions of long tailed lipids.