The TOLERANT (Low Dose TamOxifen and LifestylE Changes for bReast cANcer prevenTion, NCT06033092) trial aims to verify whether low-dose tamoxifen increases circulating levels of SHBG more than lifestyle intervention with or without intermittent caloric restriction after six months in women at an increased risk of breast cancer. The gene discussed is SHBG; the disease is breast carcinoma.