TBT. The TBT was measured 2 months post-BM grafting in WT and VavCre/JAK2^V617F KI mice (A, n = 8) and at different times after administration of tamoxifen (TM, n = 8) or vehicle (VH, n = 22) in SCLCreER^t/JAK2^V617F KI mice (B). The arrow at 15 minutes indicates that bleeding was arrested by the experimenter. Each point represents an individual mouse. The volume of blood lost in 15 minutes was measured in VavCre/JAK2^V617F KI (Aii) and in SCLCreER^t/JAK2^V617F KI mice (Bii). (C) The frequency of transient bleeding arrests observed in SCLCreER^t/JAK2^V617F KI mice at different times after administration of tamoxifen was quantified. *P < .05; **P < .004; ***P < .0001.