Jak2 V617F⁺ MPN is associated with increased circulating levels of TNF-α and higher platelet mitochondrial mass. (A) Plasma TNF-⍺ levels of healthy controls and Jak2 V617F⁺ MPN patients. (B) Representative immunoblot (left) and biochemical quantification (right) of the mitochondrial protein Tom20 between healthy controls and Jak2 V617F⁺ MPN patients. (C) Representative TEM images of platelets from healthy controls and Jak2 V617F⁺ MPN patients with black arrows depicting the significantly higher mitochondrial content in platelets from Jak2 V617F⁺ MPN patients (n = 4-12; mean plus or minus SEM). *P < .05; **P < .01; and ***P < .001. Student t test and Mann-Whitney test.