RET and pheochromocytoma: With the advancement of molecular pathogenesis, germline mutations in pheochromocytoma and/or paraganglioma (PPGL) susceptibility genes, such as NF1, RET, VHL, SDHD, SDHC, SDHB, SDHAF2, SDHA, TMEM127, MAX, EPAS1, and FH, have been identified during the past 15 years.