SF1 and adrenal cortex carcinoma: Compounds that can target SF‐1 activity, called SF‐1 inverse agonists, have been identified29, 30 and inhibited cell proliferation and steroid hormone production in vitro in human ACC cells.31 We showed in a previous study that one SF‐1 inverse agonist, compound #31, effectively inhibited cortisol production and SF‐1 target gene expression in canine adrenocortical cells in vitro.32 If SF‐1 inverse agonists will be further developed for clinical use, this may have much potential to improve the prognosis of dogs with an ACC with high SF‐1 expression.