PHT, pulmonary hypertension; EF, ejection fraction; TR, tricuspid regurgitation; MR, mitral regurgitation; NASH, nonalcoholic steatohepatitis; PSC, primary sclerosing cholangitis; PBC, primary biliary cholangitis; MELD, Model for End-Stage Liver Disease; AST, aspartate aminotransferase; ALT, alanine aminotransferase; GGT, gamma glutamyltranspeptidase; NA, not available. The gene discussed is GGTLC1; the disease is pulmonary arterial hypertension.