In addition, a potential role of MIF-T4 interactions in the pathogenesis of PAH has been suggested since T4 inhibits MIF-induced ERK 1/2 phosphorylation in macrophages; T4 inhibits MIF activation of NF κB RelA/p65 in fibroblasts; and MIF inhibits T4-induced CXCR2 mRNA accumulation in vascular smooth muscle cells131. Here, MIF is linked to pulmonary arterial hypertension.