High penetration of retrovirus-induced myeloid leukemia in p15Ink4b^fl/fl-LysMcre mice. (A) Kaplan-Meier survival curves for p15Ink4b^fl/fl-LysMcre (n = 39), p15Ink4b^fl/wt-LysMcre (n = 82), and p15Ink4b^wt/wt-LysMcre (n = 35) mice infected with the MOL4070LTR retrovirus. P values were calculated using the log-rank test. (B) Proportion of myeloid and lymphoid leukemia in wild-type (wt/wt) and targeted mice (fl/wt and fl/fl) infected with the retrovirus. (C) Distribution of myeloid leukemia subtypes in targeted and wt mice based on immunophenotype. (D) Representative pictures of a spleen from a clinically healthy mouse and an enlarged leukemic spleen with infiltrated leukemic cells. (E) Histologic analysis of paraffin-embedded sections of clinically healthy and leukemic spleens. Hematoxylin and eosin and immunohistochemical staining using anti-B220 (B220), anti-CD-13 (CD13), and anti-F4/80 (F4/80) are shown. Scale bar represents 400 μm. (F) Histologic analysis of paraffin-embedded sections of clinically healthy and leukemic liver stained with hematoxylin and eosin and anti-F4/80. Scale bar represents 200 μm.