CHEK2 pathogenic variant carriers are an important group of women to identify as they are at an increased risk of contralateral breast cancer and have a lower survival compared with non-CHEK2 pathogenic variant carriers (these data are predominantly informed by information about CHEK2 c.1100delC17–22) and could benefit from specific screening modalities such as magnetic resonance imaging23. Here, CHEK2 is linked to breast cancer.