Differentially regulated protein markers in HSC/MPPs of patients with PV and controls. (A) Volcano plot of protein intensity fold changes and P values comparing HSC/MPPs of patients with untreated PV (PV.UT.HSC/MPP) against controls (Control.HSC/MPP). (B) Normalized protein intensities for CLU, LGALS9, and SOCS2 in the subgroups of controls, patients with chronic PV without cytoreductive therapy (PVchron.UT), patients with chronic PV with HU therapy (PVchron.HU), and patients with progressed PV (PVprog). Error bars represent standard deviations. *Adjusted P < .05; **adjusted P < .01; ***adjusted P < .001. Peptide profiles for CLU, LGALS9, and SOCS2 are provided in supplemental Figure 9. (C) FACS strategy. (D) Representative FACS plots for CLU and LGALS9 in a patient with chronic PV without cytoreductive treatment (PVchron.UT), a patient with progressed PV (PVprog), and age- and sex-matched controls. FMO, fluorescence minus 1 reference. (E) Graphical summary of intracellular FACS staining experiments for CLU and LGALS9 in 6 patients with untreated chronic PV, 3 patients with progressed PV, and age- and sex-matched controls. Error bars represent standard deviations. (F) Normalized RNA reads for SOCS2 in the subgroups of controls, patients with chronic PV without cytoreductive therapy (PVchron.UT), patients with chronic PV with HU therapy (PVchron.HU), and patients with progressed PV (PVprog). Error bars represent standard deviations. *Adjusted P < .05; ****adjusted P < .0001.