CYP11B1 and adrenal cortex neoplasm: It is noteworthy that the addition of TGF-β1 to human adrenocortical tumor cell cultures has resulted in a significant inhibition of adrenocortical cell steroidogenesis, leading to the hypothesis that TGF-β1 can suppress cortisol production via the decrease of both the cytochrome P450 family 11 subfamily B member 1 (CYP11B1) mRNA levels and steroid 11β-hydroxylase activity [54].