Suggested mechanisms include the enhancement of adrenocortical cell proliferation mediated by 17β-estradiol (11), the high expression of estrogen-related receptor α (ERRα) in ACC tissues relative to normal adrenal cortex and to benign adrenal tumors (12), and the relevant role played by ERRα in 17β-estradiol and IGF-II-dependent ACC cell proliferation (13). The gene discussed is IGF2; the disease is benign neoplasm of adrenal gland.