In this study, we observe a clear positive correlation between the Mayo Risk Score and serum FGF19 levels (r = 0.509, p = 0.0004)(Fig 4A) and a negative correlations between Mayo Risk Score and serum C4 (r = -0.522, p = 0.0006)(Fig 4A) in PBC patients. The gene discussed is FGF19; the disease is primary biliary cholangitis.