Luciferase and tryptase activity are reduced in plasma, and absolute numbers of ROSA^{KIT D816V-Gluc}cells are reduced in PB of AGS-16C3F-treated xenotransplanted mice. (A) Luciferase activity after 1 week of treatment, (B) after 2 weeks, and (C) 2 weeks after stopping treatment. (D) Tryptase level measured at 4 days after the last injection of AGS-163CF. Each group comprises 4 mice. (E-H) Absolute neoplastic MC numbers in PB calculated by the equation: total WBC × % of hCD45⁺/KIT⁺ cells (fluorescence-activated cell sorter analyses of percentage of hCD45⁺/KIT⁺ in PB). Each group comprises 10 mice. Data for each animal are represented; the horizontal bar is the average. *P < .05; **P < .01 assessed by Student t test.