Mitotane is an inhibitor of steroidogenesis that suppresses the growth of adrenocortical cells. It blocks the expression of several genes that encode proteins involved in steroidogenesis and disrupts mitochondrial respiratory chain activity in human adrenocortical cells. Mitotane has anti-neoplastic actions, alone or in combination with other compounds, and suppresses cortisol synthesis, although it also has significant toxicity in the gastrointestinal tract and nervous system. It is effective against adrenocortical carcinoma and Cushing’s Syndrome in clinical trials.