HSD3B1 and breast cancer: In a separate study, the adrenal-permissive HSD3B1 variant was shown to be associated with increased rates of estrogen-driven postmenopausal breast cancer, given increased levels of circulating androstenedione that can activate the estrogen receptor, and that this genotype was associated with estrogen-driven postmenopausal breast cancer (Kruse et al. 2021).