 The most well-studied and well-established function of viroporins is the permeabilization of the cell membrane to ions and small solutes.Before viroporins themselves were understood as a class, it was well known that many viruses induce membrane permeabilization in infected cells; viroporins are at least partially responsible for this effect, particularly when it occurs late in the viral replication cycle.Viroporins expressed transgenically, in the absence of their virus of origin, induce the same effect, a feature that has facilitated viroporin discovery.