CYP21A2 and hereditary pheochromocytoma-paraganglioma: It was found that in PCPG (pheochromocytoma/paraganglioma), there was a co-expression between SULT1E1 and CYP17A1 (SULT1E1-CYP17A1), SULT1E1-CYP21A2, SULT2A1-CYP17A1, and SULT2A1-CYP21A2 genes, with Pearson correlation coefficients (R) equal to 0.60, 0.56, 0.81, and 0.73, respectively.