Some large cases and control studies carried out recently have found rare missense variants in significant excess in CHEK2. According to a study which involves 13,087 BC cases and 5,488 controls, the odds ratio (OR) (95% confidence interval, CI) for CHEK2 rare missense variants was 1.36 (CI: 0.99–1.87) and 1.51 (CI: 1.02–2.24), considering only the functional domains (Han et al., 2013; Decker et al., 2017). The gene discussed is CHEK2; the disease is breast cancer.