DRAG mice develop human hepatocytes. A) Plasma levels of human transferrin in DRAG mice (n = 14) at 14 weeks post-infusion of HSC. No human transferrin was detected in serum from control (non-HSC infused) DRAG mice (n = 7). Data represent mean ± SD of mice analysed individually (left panel). Kinetics of human transferrin in plasma of two DRAG mice analysed individually (right panel). B) Staining of liver sections with anti-human transferrin. Arrow shows the presence of human hepatocytes. C) Identification of human hepatocytes in livers of HSC-infused DRAG mice using human anti-Hep Par-1 (red) and counterstained with DAPI (DNA, blue). D) Frequency of human hepatocytes in livers of DRAG mice as measured by FACS using anti-human albumin. Left panel shows binding of anti-human albumin to primary human hepatocytes (black histogram) but not to mouse hepatocytes (white histogram). Middle and right panels show anti-human albumin staining in livers of control (non-HSC infused) and in HSC-infused DRAG mice, respectively. Data represent mean and interval frequencies from three mice analysed individually.