These two study groups were the first to contribute prospective data to the discussion about HRT in BRCA mutation carriers, focusing exclusively on mutations in BRCA1. In the metaanalysis by Marchetti et al., another smaller retrospective study was additionally included and a lower breast cancer risk associated with the use of ET compared to EPT was observed (Marchetti et al. 2018). The gene discussed is BRCA1; the disease is breast carcinoma.