For example, enzymes involved in catecholamines synthesis (Tyrosine Hydroxylase (TH), Dopamine-β-Hydroxylase (DBH), DOPA decarboxylase (DCC)) are overexpressed in pheochromocytoma (Jarrott and Louis, 1977; Isobe et al., 1998; Eisenhofer et al., 2008; Houy et al., 2022). This evidence concerns the gene TH and pheochromocytoma.