Translational studies show that approximately 60% of PCC and PGL cases have either germline or somatic mutations in one of 13 suggested disease causing loci; SDH subunits A, B, C and D, SDHAF2, VHL, EPAS1, RET, NF1, TMEM127, MAX and H-RAS[8]–[20]. This evidence concerns the gene MAX and adrenal gland pheochromocytoma.