PLAU and infection: To test for the sensitivity to infection with HCV in the chimeric mice relative to the infectivity in chimpanzees , we inoculated intravenously (i.v.)a ten-fold dilution series of HCV (strain H) plasma containing a beginning titer of 104.5 50% chimpanzee infectious doses (CID50) per mL [27] into engrafted MUP-uPA/SCID/Bg mice (four mice per dilution) 30 days post engraftment.