Cd45.1 wt mice

WT mice (C57BL/6) for the drug screen and EPO injection assays were purchased from The Jackson Laboratory. CD45.1⁺ WT mice for BM transplantation were purchased from Charles River Laboratories. Jak2^V617F floxed (Jak2^VF/+) hematopoietic-specific knockin mice (Jak2^VF/+Vav-Cre) (originally reported in ref. 42 (link)), Plek2-KO, and Jak2^VF/+Vav-Cre, Plek2-KO mice were previously reported (12 (link)). Pten floxed (Pten^fl/fl) mice were purchased from The Jackson Laboratory. These mice were crossed with Mx-Cre mice (The Jackson Laboratory) to generate hematopoietic-specific Pten-KO mice. These mice were further crossed with Plek2-KO mice to generate Pten^fl/flMx-Cre, Plek2-KO mice. To test the CBCs, peripheral blood (75 μL from each mouse) was collected from retroorbital veins in EDTA-treated minicollection tubes (Greiner Bio-One GmbH). The Hemavet 950 complete blood counter (Drew Scientific) was used to determine CBCs. For pathologic analyses, the leg bones, spleen, and lungs were collected from euthanized mice and treated with formalin solution (MilliporeSigma) before H&E staining.