To identify the cellular and molecular basis for megakaryocyte-biased hematopoiesis in myelofibrosis without bias from pre-selected cell surface antigens, high-throughput scRNA-seq was performed on 135,929 individual CD34+ lin– HSPCs from patients with JAK2V617F+ or mutCALR+ myelofibrosis (93,157 cells, n = 15) according to World Health Organization (WHO) criteria (Arber et al., 2016) and age-matched healthy donors (42,772 cells, n = 6) by using the 10x Genomics Chromium platform (Table S2). Here, CD34 is linked to myelofibrosis.