BM-MSC from PV patients co-cultured with PBMC released (i) had higher macrophage-derived cytokine (MDC; p-value ≤0.05) and vascular endothelial growth factor (VEGF; p-value ≤0.01) levels, compared with BM-MSC from PV patients alone; and (ii) lower FMS-like tyrosine kinase 3 ligand (Flt-3 L; p-value ≤0.01) levels than MSC from HD co-cultured with PBMC (Figure 3A). The gene discussed is FLT3; the disease is acquired polycythemia vera.