CXCL1 and acquired polycythemia vera: Previous ET patient data concluded that relatively low levels of chemokines, pro- or anti-inflammatory cytokines, or hematopoietic growth factors were present in patients with ET compared to those with PV and MF.8 However, these studies often had very few patients (n = 5 in Ho et al,14 n = 21 in Pourcelot et al,16 n = 15 in Boissinot et al13) and only one of these studies measured GRO-α, EGF, or eotaxin levels14 with no significant changes observed, likely due to the small number of ET patients sampled (n = 5).