IR can instigate an upsurge of inflammatory cytokines associated with obesity, including IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, tumor necrosis factor-α, and interferon, which have been robustly linked to the development of PAH [48, 49]. This evidence concerns the gene IL1B and obesity due to melanocortin 4 receptor deficiency.