The expression analysis of FDX1 in pan-cancers using the TIMER database showed that FDX1 mRNA expression was significantly lower in BRCA (breast invasive carcinoma), CHOL (cholangiocarcinoma), COAD (colon adenocarcinoma), ccRCC, KICH (kidney chromophobe), KIRP (kidney renal papillary carcinoma), LUAD (lung adenocarcinoma), LUSC (lung squamous cell carcinoma), PCPG (Pheochromocytoma and Paraganglioma), READ (rectum adenocarcinoma), and THCA (thyroid carcinoma) samples compared with the corresponding normal samples (Figure 2A). This evidence concerns the gene FDX1 and cholangiocarcinoma.