Compared with the control group, PV patients exhibited increased levels of GM-CSF (p = 0.0019), IFN-α2 (p = 0.0005), IFN-γ (p = 0.0164), IL-12p70 (p = 0.0007), IL-17A (p = 0.0164), IL-5 (p = 0.0112), IP-10 (p = 0.0166), MIP-1α (p = 0.0003), MIP-1β (p = 0.00315) and TNF-α (p < 0.0001) (Fig. 1). This evidence concerns the gene CCL4 and acquired polycythemia vera.