The following variables were not retained: HER2 status (HER2+, HER2−), type of surgery (ablatio, breast conserving), chemotherapy (yes, no), alcohol consumption (no alcohol consumption, <19 g/day, > = 19 g/day), body mass index (BMI) (18.5–<25 kg/m2, <18.5 kg/m2, 25–<30 kg/m2, > = 30 kg/m2), diabetes mellitus (yes, no), cardiovascular disease (yes, no), occupational status (low, medium, high), formal education (low, medium, high), leisure time physical activity since age 50 (<28 metabolic equivalent hours (METh) per week, > = 28 METh/week). The gene discussed is ERBB2; the disease is diabetes mellitus.