Breast cancer susceptibility genes with high-risk variant alleles such as breast cancer susceptibility genes (BRCA1, BRCA2); tumour protein p53 (TP53); phosphatase and tensin homologue (PTEN); serine/Threonine kinase 1 (STK11); and cadherin 1 (CDH1) are some of the genes that will give rise to the relative risk of breast cancer [30]. Here, BRCA1 is linked to breast cancer.