The original IBIS/Tyrer–Cuzick model considers the following 14 risk factors: age, body mass index, age at menarche, age of first live birth, age of menopause, parity, hormone replacement therapy, breast density, atypical ductal hyperplasia, lobular carcinoma in situ, prior breast biopsies, family history of breast cancer (including age at diagnosis and bilateral breast cancer), family history of ovarian cancer, and genetic testing (BRCA1/2 and SNPs). Here, BRCA1 is linked to atypical ductal hyperplasia.