A discovery in mice reveals why fasting enhances a type of breast cancer treatment — a hormone-signalling pathway and gene-expression changes have key roles.

Beneficial effects of fasting combined with endocrine therapy for oestrogen receptor-α-expressing breast cancers can be recapitulated using exogenous glucocorticoid receptor ligands instead of fasting to reduce harmful effects.

While Estrogen receptor alpha (ERα)+ breast cancer treatment is considered effective, resistance to endocrine therapy is common. Since ERα is still...