TMPRSS2 and infection: By contrast, TMPRSS2 was shown to enhance viral entry and replication of MERS-CoV (Gierer et al., 2013; Shirato et al., 2013), although the peak titers of the recombinants in Vero/TMPRSS2 cells were similar, with a slight delay in replication in the Amibara S recombinants at 1-day post-infection (Figure 3C).