IL6 and pulmonary arterial hypertension: Myo-inositol has been proposed to modulate reduced interleukin-6 levels (Bizzarri et al., 2020), a cytokine involved in the development and progression of (Steiner et al., 2009), 2-hydroxybutyrate is a marker of the ketone metabolism that characterizes PAH (Mey et al., 2020), whereas leucine reduction may be related to glutamine metabolism (Bertero et al., 2019).