Analysis from the TIMER database indicated that CDH18 expression was significantly higher in cancer types such as lung squamous cell carcinoma (LUSC), liver hepatocellular carcinoma (LIHC), lung adenocarcinoma (LUAD), pheochromocytoma and paraganglioma (PCPG), uterine corpus endometrial carcinoma (UCEC), and breast invasive carcinoma (BRCA) compared to adjacent normal tissues (Figure 1A). This evidence concerns the gene CDH18 and hereditary pheochromocytoma-paraganglioma.