JAK2 and leukemia: After blood count confirmation (Table 2), the quantification of CD9 in VSELs-like cells purified from the peripheral blood cells of patients diagnosed with JAK2 (V617F) showed that its expression was significantly increased in the leukemia patients’ cells in comparison to the control cells isolated from healthy donors (1.1 ± 1.22% vs. 0.16 ± 0.18% of lineage-negative cells, respectively) (Table 2).