We analyzed KLRD1 gene expression using RNA sequencing data from TCGA, revealing significantly lower expression in breast invasive carcinoma (BRCA), cholangiocarcinoma (CHOL), colon adenocarcinoma (COAD), liver hepatocellular carcinoma (LIHC), lung adenocarcinoma (LUAD), lung squamous cell carcinoma (LUSC), prostate adenocarcinoma (PRAD), thyroid carcinoma (THCA), and uterine corpus endometrial carcinoma (UCEC), compared to normal tissues. This evidence concerns the gene KLRD1 and cholangiocarcinoma.