Tumor-initiating capacity of tumor cells found in p53^−/−VAV1-Tg and p53^−/− mice. (A) Summary of donor mice, showing genotypes and various experimental parameters. The summary of transplanted T-LBL donor mice (i) and Lym donor mice (ii). (B) OS of nude mice transplanted intraperitoneally with T-LBL of indicated genotypes (p53^−/− V-Del, n = 13; p53^−/− V-Fus, n = 26; and p53^−/−, n = 17). (C) OS of nude mice that were initially and then secondarily transplanted with Lym from p53^−/−VAV1-Tg mice (p53^−/− V-Del, n = 46; p53^−/− V-Fus, n = 31; 2nd p53^−/− V-Del, n = 20; 2nd p53^−/− V-Fus, n = 40). (D) HE-stained sections from nude mice transplanted with T-LBL or Lym of indicated genotypes. Original magnification: ×4; insets, ×100. Scale bars, 20 µm. (E) Characterization of donor-derived cells in spleens and lymph nodes. (i) Representative flow cytometric analysis for CD3, CD4, and CD8 to determine immunophenotypes of tumor cells, and H2Kd and H2Kb, MHC class I molecules to determine recipient-derived (ν/ν) and donor-derived (C57BL/6) cells, respectively. (ii) Percentages of donor cells in lymph nodes and spleens of nude mice transplanted with T-LBL. (iii) Percentages of donor cells in lymph nodes and spleens of nude mice transplanted with Lym. (F) Immunohistochemical analysis for CD3, CD4, and CD8 in spleens of nude mice transplanted with T-LBL (i) and Lym (ii) from p53^−/−VAV1-Tg mice. Original magnification ×40. Scale bars, 20 µm. The percentage at the bottom right corner is positivity in the tumor cells.