CLDN1 and infection: Intriguingly, monoclonal antibodies against CLDN1 were shown to inhibit HCV entry, cell-cell-transmission and virus-induced signaling events in absence of detectable toxicity (Mailly et al., 2015; Yamashita et al., 2015), and they were also effective in hindering infection by all major HCV genotypes and quasispecies (Fofana et al., 2010).