Increased incidence of BC has also been related to mutations in the tumor-suppressor gene phosphatase and tensin homolog (PTEN) and the DNA mismatch repair gene MutS homolog 2 (MSH2), which are seen in Cowden and Lynch syndromes, respectively (Riegert-Johnson et al., 2010; van der Post et al., 2010). This evidence concerns the gene MSH2 and breast cancer.