Von Willebrand analysis in JAK2^V617F mice. (A) Plasma concentrations of VWF in VavCre/JAK2^V617F (Ai, KI, n = 21), SCLCreER^t/JAK2^V617F (Aii, TM, n = 4 per group), and their controls. Mouse plasma samples were analyzed 2-3 months after BM graft. *P < .03. (Bi) Representative electrophoreses (n = 3) of the multimeric structure of VWF from 2 different WT mice and 4 different VavCre/JAK2^V617F (KI). The dotted line square represents the decreased intensity of the high-molecular-weight bands (HMW). Quantification of HMW (Bii) and low-molecular-weight bands (LMW) (Biii) of VWF from 9 VavCre/JAK2^V617F (KI) and WT. **P < .002. (Ci) Representative electrophoreses of the multimeric structure of VWF from SCLCreER^t/JAK2^V617F mice at D6 and D60 compared with controls (VH). Quantification of HMW (Cii) and LMW bands (Ciii) of VWF from 4 SCLCreER^t/JAK2^V617F per group at different times after treatment by tamoxifen.