Somatic mosaicism of GNAS has been implicated in the pathogenesis of McCune-Albright syndrome-related adrenal Cushing syndrome manifesting as bilateral macronodular adrenocortical disease (e.g., PBMAH), as well as a bimorphic cortical nodular disease and rare adenomas (55). The gene discussed is GNAS; the disease is ACTH-independent Cushing syndrome.