CCL19 and intrahepatic cholangiocarcinoma: As illustrated in the flowchart (Figure 1A), 83 individuals with ICC were obtained from GSE89749 and classified into the high‐HEV and low‐HEV groups as per the ssGSEA scores from the ssGSEA algorithm, which was based on 10 HEV genes obtained by literature search (CHST4, CCL21, CCL19, IL33, ICAM1, MADCAM1, TSPAN7, MEOX2, ANKRD53, and ZNF280C).