Abstract: Liver cirrhosis consists of an asymptomatic compensated phase and a decompensated phase, which can cause two pulmonary vascular complications: hepatopulmonary syndrome (HPS) characterized by hypoxia, intrapulmonary microvasculature dilatation, angiogenesis and arterio-venous malformations (AVMs) [1Koch D.G. Fallon M.B. Hepatopulmonary syndrome.Clin Liver Dis. 2014; 18: 407-420http://dx.doi.org/10.1016/j.cld.2014.01.003Summary Full Text Full Text PDF PubMed Scopus (18) Google Scholar]; and portopulmonary hypertension (PoPH) characterized by increased pulmonary vascular resistance and pulmonary arterial hypertension (PAH) in the absence of other etiologies of PAH [2Iqbal S. Smith K.A. Khungar V. Hepatopulmonary syndrome and portopulmonary hypertension.Clin Chest Med. 2017; 38: 785-795http://dx.doi.org/10.1016/j.ccm.2017.08.002Summary Full Text Full Text PDF PubMed Scopus (12) Google Scholar]. Previous studies have shown that PoPH and HPS are associated with markedly reduced bone morphogenetic protein (BMP) 9/10 [3Rochon E.R. Krowka M.J. Bartolome S. Heresi G.A. Bull T. Roberts K. et al.. BMP 9/10 in pulmonary vascular complications of liver disease.Am J Respir Crit Care Med. 2020; http://dx.doi.org/10.1164/rccm.201912-2514leCrossref PubMed Scopus (2) Google Scholar, 4John M. Kim K.J. Bae S.D.W. Qiao L. George J. Role of BMP-9 in human liver disease.Gut. 2019; 68: 2097-2100http://dx.doi.org/10.1136/gutjnl-2018-317543Crossref PubMed Scopus (5) Google Scholar] and increased soluble endoglin (sEng) levels [5Owen N.E. Alexander G.J. Sen S. Bunclark K. Polwarth G. Pekpe-zaba J. et al.Reduced circulating BMP10 and BMP9 and elevated endoglin are associated with disease severity, decompensation and pulmonary vascular syndromes in patients with cirrhosis.EBioMedicine. 2020; 56102794http://dx.doi.org/10.1016/j.ebiom.2020.102794Summary Full Text Full Text PDF PubMed Scopus (1) Google Scholar]. Approximately 4–40% of cirrhotic patients could develop into HPS [6Soulaidopoulos S. Cholongitas E. Giannakoulas G. Vlachou M. Goulis I. Review article: update on current and emergent data on hepatopulmonary syndrome.World J Gastroenterol. 2018; 24: 1285-1298http://dx.doi.org/10.3748/wjg.v24.i12.1285Crossref PubMed Scopus (14) Google Scholar] and PoPH can develop in 1–6% of patients with portal vein hypertension [7Savale L. Guimas M. Ebstein N. Fertin M. Jevnikar M. Renard S. et al.. Portopulmonary hypertension in the current era of pulmonary hypertension management.Journal of Hepatology. 2020; http://dx.doi.org/10.1016/j.jhep.2020.02.021Summary Full Text Full Text PDF PubMed Scopus (6) Google Scholar]. Both of these complications can increase the mortality rate in liver cirrhotic patients and there are few effective precautionary or therapeutic measurements except liver transplantation [8Cosarderelioglu C. Cosar A.M. Gurakar M. Pustavoitau A. Russell S.D. Dagher N.N. et al.Portopulmonary hypertension and liver transplant: recent review of the literature.Exp Clin Transplant. 2016; 14: 113-120PubMed Google Scholar, 9Sendra C. Carballo-Rubio V. Sousa J.M. Hepatopulmonary syndrome and portopulmonary hypertension: management in liver transplantation in the horizon 2020.Transplant. Proc. 2020; http://dx.doi.org/10.1016/j.transproceed.2020.02.057Crossref PubMed Scopus (1) Google Scholar]. The study recently published in EBioMedicine by Owen and co-workers contribute to the literature from three aspects.