Patients with PAH show evidence of decreased monocyte activation through the inhibition of nuclear factor kappa B cell (NF-ĸB) signaling, interleukin-6 (IL-6), CC chemokine ligand-3 (CCL3, previously macrophage inflammatory protein 1-alpha), and vascular endothelial growth factor (VEGF) [44]. Here, IL6 is linked to pulmonary arterial hypertension.