TMPRSS2 and influenza: Several recent findings suggest that TMPRSS2 is a potential target for antiviral intervention: Expression of this protease is essential for spread of several FLUAV strains in mice [16–18], TMPRSS2 polymorphisms which increase protease expression are linked with severe influenza in humans [19] and a serine protease inhibitor which blocks TMPRSS2 (and other serine proteases) protects rodents from SARS-CoV pathogenesis [15].