Overexpression of TMPRSS12 enhances aMPV/B replication. (A and C) aMPV/B replication kinetics in different cells overexpressing TMPRSS12 were tested up to 96 h p.i. (B and D) At 72 h p.i., the supernatant in infected cells overexpressing TMPRSS12 was collected to determine titer. (E and G) aMPV/B replication kinetics in Vero cells overexpressing hepsin or TMPRSS2 were tested up to 96 h p.i. (F and H) At 72 h p.i., the supernatant in infected cells overexpressing hepsin or TMPRSS2 was collected to determine titer. **, P < 0.05; ***, P < 0.005; #, P > 0.05 (nonsignificant).