Based on the results of the TIMER2.0 database, FDX1 expression was significantly lower in BRCA (breast invasive carcinoma), COAD (colon adenocarcinoma), CHOL(cholangiocarcinoma), HNSC-HPV (head and neck cancer), KIRP (kidney renal papillary carcinoma), KICH (kidney chromophobe), KIRC, LUAD (lung adenocarcinoma), LUSC (lung squamous cell carcinoma), PCPG (pheochromocytoma and paraganglioma), PEAD (rectum adenocarcinoma), THCA (thyroid carcinoma) and SKCM (skin cutaneous melanoma) than in adjacent normal tissue. Here, FDX1 is linked to pheochromocytoma.