PCK2 and paraganglioma: PCK2 was highly expressed in seven cancer types, including bladder urothelial carcinoma (BLCA), breast invasive carcinoma (BRCA), cervical and endocervical cancer (CESC), esophageal carcinoma (ESCA), glioblastoma multiforme (GBM), head and neck squamous cell carcinoma (HNSC), pheochrocytoma and paraganglioma (PCPG).