RLN2 and pulmonary arterial hypertension: In another study with chronic HFpEF patients, Emmens et al. (2017) could not determine an association between circulant relaxin-2 levels and pulmonary artery pressure (PAP) and right-sided heart function, although relaxin-2 plasma levels were detectable in all patients and showed higher levels (median 82.3 pg/mL) than previous studies (Table 2), suggesting an increase in circulant relaxin-2 levels during pulmonary hypertension [104].