By comparing 36 non-paired CCA (30 iCCA and 6 eCCA) with the non-tumour tissues (https://portal.gdc.cancer.gov/), we showed that the USP22 mRNA was significantly upregulated in CCA (p < 0.05) (Supplementary Fig. 1A and 1B), but had no significant correlation with copy numbers of USP22 with either shallow deletion, DNA diploid, or amplification (Supplementary Fig. 1C), hinting the non-genetic regulatory role of USP22 in CCA. The gene discussed is USP22; the disease is cholangiocarcinoma.