Fig. 2: Overexpression of MTCP1 drives a lethal CLL-like leukemia.

A Longitudinal flow cytometry analysis of a representative Eµ-MTCP1 mouse showing progressive development of a CD45⁺/CD5⁺/CD19⁺ and CD19⁺/B220^dim CLL-like population in the blood. B Eµ-MTCP1 mice (Z36, n = 54; Z20, n = 36) were followed monthly by flow cytometry for disease progression as described in (A). Varying ratios of hemopathies were observed, including expansion of CD5⁺/CD19⁺ (CLL-like, pink) cells, CD5⁺/CD19⁻ cells (T cells, orange), CD5⁻/CD19⁻ (myeloid, green) cells, or CD19⁺/B220^dim only CLL-like cells (tan). C Kaplan–Meier estimation of median time to disease onset in Eµ-MTCP1 mice (Z36 – red, n = 54; Z20 – blue, n = 36). Disease onset was defined as detection of >20% CD5⁺/CD19⁺ and CD19⁺/B220^dim CD45⁺ cells in the blood determined by flow cytometry. Median time from birth to disease onset was shorter in Eµ-MTCP1 mice from the Z36 founder line (7.7 months) than from the Z20 line (16.7 months; p < 0.001). D Pie chart illustrating cause of death for Eµ-MTCP1 mice (Z36, n = 54; Z20, n = 36). Cause of death for a majority of Eµ-MTCP1 mice can be attributed to lethal progression of their disease burden. “ERC” = blue, mice met predefined early removal criteria. “Spontaneous” = purple, mice displayed disease progression identified by flow cytometry but had a spontaneous and unpredictable death. “Other” = green, mice died without measurable disease. E Kaplan–Meier estimation of median survival in Eµ-MTCP1 mice (Z36 - red, n = 54; Z20 - blue, n = 36). The median survival time was 10.8 months (95% CI: 9.5–12) for Eµ-MTCP1 founder line Z36 and 14.5 months (95% CI: 13.1–16) for founder line Z20 (p < 0.001). Representative survival of wildtype mice (black, n = 54) is shown as reference. P values (in C and E) determined by estimates from a Cox proportional hazards model.