especially for large systems. For fusion pores with radii between ∼1nm and ∼4nm, Jackson and collaborators proposed that a toroid could deform into a catenoid-like surface, overestimating the free energy. 9 Using large DOPC bilayers (45x45nm) with an inter-membrane distance of ∼10nm, Yoo et al. showed that the fusion pore exhibits a bowing feature related to the slow relaxation of the lipids in regions far from the fusion pore. This characteristic could, in principle, help to stabilize large fusion pores.