In addition, by searching the online TCGA database (https://cancergenome.nih.gov/), we performed additional analyses of the expression of LUM, PRDX2, BGN, and PPP3CA in CCA based on the patient's race, which were depicted in Fig. 2, and the statistical significance for the comparison of the expression of LUM, PRDX2, BGN, and PPP3CA based on the patient's race is summarized in Supplementary table 1. The gene discussed is PPP3CA; the disease is cholangiocarcinoma.