While selenium-deprived diets have not been tested in breast cancer models, Eagle et al showed a therapeutic effect of selenium deprivation in leukaemia models, while Alborzinia et al inhibited cellular selenoprotein P uptake to decrease the expression of selenoproteins and induce ferroptosis in neuroblastoma (Alborzinia et al, 2023; Eagle et al, 2022). The gene discussed is SELENOS; the disease is leukemia.