This 29.5 kB deletion between exon 5 in APOBEC3A and exon 8 in APOBEC3B is linked to increased risk for breast cancer, hepatocellular carcinoma (HCC) and epithelial ovarian cancer, whereas this deletion polymorphism is not involved with clinical outcome of mammary cancer regardless of APOBEC3B mRNA levels [13, 86–89]. This evidence concerns the gene APOBEC3A and breast cancer.