CCL2 and essential thrombocythemia: These findings, namely PV and ET patients with relatively low CCL2 expression levels (low inflammatory burden) and PMF and Post-PV/ET-MF patients with high CCL2 expression levels (high inflammatory burden), suggest the functional relevance of this SNP in MF cells (highest chemokine levels) and the inflammatory role of CCL2 gene expression at the onset and development of PMF and Post-PV/ET-MF.