Numerous studies are focused on specific populations, such as 237 patients from a reported population-based south Swedish triple-negative breast cancer cohort profiled by RNA sequencing and whole-genome sequencing included in “Molecular analyses of triple-negative breast cancer in the young and elderly” or a population-based Estonian biobank (over 150,000) and breast cancer-affected cases from Latvia chosen to assess the spectrum and frequency of CHEK2 variants in the breast cancer-affected and general population in the Baltic states region [91,92]. The gene discussed is CHEK2; the disease is breast cancer.