To better characterize the function of PNMT in PCC/PGL, we analyzed a large (125 samples) public PCC/PGL microarray expression profile dataset (GSE19987) with a variety of mutations in pheochromocytoma susceptibility genes such as RET, VHL, SDHB and SDHD [22]. Here, RET is linked to hereditary pheochromocytoma-paraganglioma.