These include metomidate labeled with 11C or 18F that relies on the detection of extracortical adrenal tissue (17,18); fluorine-labeled ligands for CYP11B2, an enzyme involved with aldosterone production, which is overexpressed in functional adenomas (18,19); and most recently CXCR-4 ligand analogs (notably 68Ga-pentixafor), imaging overexpression of the receptor in adrenal adenomas (20–22). This evidence concerns the gene CXCR4 and adrenal cortex adenoma.