LSD1 overexpression in quiescent HSCs accelerates γ-irradiation-induced development of T-LBL. (A) Kaplan-Meier survival curves of line 6 (n = 10) and line 3 (n = 8) of LSD1 transgenic and B6J control mice (n = 8) with (solid lines) or without (broken lines) γ-irradiation. P values were determined by the log-rank test. (B) Representative photographs of the spleen, thymus, and kidney dissected from LSD1 transgenic (lines 6 and 3) and control mice. (C) Representative photographs of histopathologic sections of the indicated organs. The diagnosis of T-LBL was made by outside experts of animal pathology. (D) Surface marker expression of bone marrow cells from LSD1 transgenic and control mice. *P < .05 and **P < .01 determined by a 1-way ANOVA with the Bonferroni post hoc test (n = 3). (E) Graphical abstract: LSD1 overexpression generates preleukemic HSCs with T-lineage priming, which are transformed to T-cell malignancy by second hits such as γ-irradiation.