Metomidate is an inhibitor of the enzyme 11β-hydroxylase (CYP11B1) and aldosterone synthase (CYP11B2), which are found in the adrenal cortex, and 11C-labeled metomidate ([11C]MTO) is currently used for imaging of adrenocortical carcinoma and primary aldosteronism (PA) [24]. This evidence concerns the gene CYP11B2 and primary aldosteronism.