Further survival analysis of DEGs identified several potential biomarker genes for CCA including MLL11, MDK, DEPDC1, SLC35E4, PLXDC1, PACS1, PIWIL4, GLUD1, all have AUC ∼1 with very low p-value (Supplementary Table S6). The gene discussed is PIWIL4; the disease is cholangiocarcinoma.