CLK4 expression varied in different cancer datasets, among which the expression was significantly elevated in CHOL, glioblastoma multiforme (GBM), HNSC, KIRC, KIRP, LIHC, PRAD, and STAD; Conversely, CLK4 transcription was reduced in BLCA, breast invasive carcinoma (BRCA), lung squamous cell carcinoma (LUSC), pheochromocytoma and paraganglioma (PCGC), thyroid carcinoma (THCA) and uterine corpus endometrial carcinoma (UCEC) (Fig. 5). This evidence concerns the gene CLK4 and hereditary pheochromocytoma-paraganglioma.