For instance, Cluster1 showed the highest expression level of a series of previously reported metastasis or progression related genes in ICC, such as TMPRSS4, S100A4, S100P, PTEGS, MUC1, COX-2, IL-6 and CEACAM6 (Figure S9) 45-50. Here, IL6 is linked to intrahepatic cholangiocarcinoma.