CD34 and myeloproliferative disorder: In MPN, HMGA1 is overexpressed in at least six independent cohorts [48], including MPN CD34+ hematopoietic stem and progenitor cells (HSPCs), compared to healthy, age-matched controls [90,91,92,93], peripheral blood mononuclear cells (PBMCs) [91,92], and even platelet transcripts (Table 1) [94].