IL-27 Tg mice have an increased number of CD34⁻KSL cells in BM, but they failed to show any HSC activity. (A) Cells from BM of wild-type and IL-27 Tg no. 1 and/or no. 6 mice (n = 3) at 8 weeks of age were stained with various combinations of antibodies or Hoechst 33342 and analyzed by flow cytometry. (B) HSC function in BM cells of IL-27 Tg mice were analyzed by transplantation assays. Chimerism of IL-27 Tg no. 6 mouse-derived WBCs in competitive repopulation assays at 4 months after transplantation (n = 10). Lineage distribution of IL-27 Tg no. 6 mouse- or wild-type mouse–derived cells was determined. * indicates P < .05, compared with wild-type mouse–derived cells. (C) Lineage distribution of IL-27 Tg no. 6 mouse- or wild-type mouse–derived cells in wild-type or Tg recipients at 3 months after transplantation without competitor cells. * indicates P < .05, compared with wild-type to wild-type transplantation. Data are shown as the mean (± SD).