It is worth highlighting the negative correlation between irisin and PVR, which further accentuates the potential of irisin as a promising biomarker that reflects pulmonary vascular remodeling in PAH, as PVR is closely associated with right‐heart function and vascular remodeling.[25, 26] Our in vivo studies demonstrate that PAH development and pulmonary vascular remodeling negatively correlate with irisin expression levels. The gene discussed is FNDC5; the disease is pulmonary arterial hypertension.