Requirement of AID for BCR-ABL1⁺ B-ALL initiation and maintenance upon inflammatory stimulation. (A-B) AID WT or AID KO BCR-ABL1⁺ B-ALL cells were treated with LPS (25 µg/mL) or PBS, then cultured in a 96-well plate with FBS-deficient culture medium for 72 hours. (A) Cell viability was determined by CCK-8 assays. (B) Cell apoptosis was measured by flow cytometry; the histogram shows the percentages of apoptotic cells. (C) The cell cycle of AID WT and AID KO BCR-ABL1⁺ B-ALL cells treated with LPS (25 µg/mL) or PBS was measured by flow cytometry. The histogram shows the percentages of each period. (D) Schematic representation of BCR-ABL1⁺ B-ALL mouse models derived from secondary transplantation of AID WT or AID KO BCR-ABL1⁺ B-ALL mouse model. (E) Kaplan-Meier survival curves for the indicated recipient mice (n = 6 per group). (F) Monitoring the peripheral blood percentage of GFP⁺ cells in the recipient mice transplanted with the indicated leukemic cells on day 7 and day 14 posttransplantation. (G) Leukemia burden was determined by measuring percentages of GFP⁺ cells in BM, SP, LN, liver, lung, and brain in the recipient mice at day 14 after transplantation. The data are representative of at least 3 independent experiments. Error bars represent the mean ± standard error of the mean. *P < .05, **P < .01, ***P < .001. ns indicates no significant differences.