We finally performed a Mendelian randomization analysis on the expression of WDPCP gene (ENSG00000115507) and liver conditions using cis-eQTL data (Table 5) and identified a link between expression of WDPCP with liver fibrosis and cirrhosis (β = − 0.20; 95% CI − 0.39, − 0.01; P-value = 0.04) as well as liver and bile duct cancer (β = 0.0003; 95% CI 3.27 × 10–05, 5.85 × 10–04; P-value = 0.02). The gene discussed is WDPCP; the disease is bile duct cancer.