MEIS1 and myeloproliferative disorder: This analysis focused on genes (Srpk2, Hes1, Mtor, Pdp1, Meis1, Gfi1, Foxo3, Stra13, Hif1α, and Cebpε) involved in HSC proliferation; maintenance of quiescence, growth, and stem cell exhaustion; and development of myeloproliferative disorder in young and geriatric mice.