HAMP and cholangiocarcinoma: Interestingly, previous studies reported that HAMP was downregulated in cholangiocarcinoma [19] and liver hepatocellular carcinoma [20] and upregulated in breast cancer, pancreatic adenocarcinoma [21], prostate cancer, and colorectal adenocarcinoma [22] However, the roles of HAMP and its association with immune cell infiltration in ccRCC are unexplored.