The main one is older age, followed by socio-economic status, genetic factors (carrying mutated BRCA1 or BRCA2 genes), positive family history, exposure to sex hormones (early menarche, late menopause, older age at first birth, long-term hormone replacement therapy or hormonal contraception), overweight and obesity and exposure to ionizing radiation (chest radiotherapy before the age of 30) [20,26]. Here, BRCA1 is linked to obesity due to melanocortin 4 receptor deficiency.