CTL killing and hepatocyte replacement. CTL killing and hepatocyte replacement. The kinetics of clearance of infected hepatocytes have been calculated by assuming that CTL killing is a first-order reaction. Each point indicates the fraction of the initial number of infected hepatocytes that were killed in the preceding 24-h period. The different curves were determined using t1/2 values for killing that would produce 99% loss of infected hepatocytes in the indicated times. Christoph Seeger, and William S. Mason Microbiol. Mol. Biol. Rev. 2000; doi:10.1128/MMBR.64.1.51-68.2000