Analysis of mice treated with INC424, HU, or vehicle and transplanted with JAK2-V617F mutant (from MxCre;FF1 mice with a PV phenotype) and Jak2 wild-type (from UBC-GFP mice) BM cells in a 1:1 ratio. (A) Body weight during treatment. Black indicates vehicle (0.5% hydroxypropyl methylcellulose); bright blue, INC424 30 mg/kg BID; dark blue, INC424 90 mg/kg BID; orange, HU 100 mg/kg BID; and red, HU 200 mg/kg BID. (B) Spleen weights. Color coding is as in panel A. (C) Blood counts and flow cytometry data showing the chimerism (percentage of GFP⁻ cells) after 21 days of treatment. (D) Reticulocyte counts. Color coding is as in panel A. (E) Chimerism in BM (top panel) and spleen (bottom panel) after 21 days of treatment. One-way ANOVA is shown for comparisons between the vehicle- and INC424- or HU-treated cohorts. ns indicates not significant.*P ≤ .05; **P ≤ .01; ***P ≤ .001.