The immunohistochemistry (IHC) staining on tissue microarray also confirmed that METTL14 staining was decreased in CCA at the protein level (Supplementary Fig. 3A) and its downregulation displayed a significant association with poor cancer-specific survival in CCA (Log-Rank P = 0.045; Supplementary Fig. 3B). This evidence concerns the gene METTL14 and cholangiocarcinoma.