PTEN and Cowden disease: Apart from the Hereditary Breast and Ovarian Cancer Syndrome caused by mutations in BRCA1 and BRCA2, these include Li-Fraumeni Syndrome (TP53) [9], Cowden Syndrome (PTEN) [10], Peutz-Jeghers Syndrome (STK11) [11, 12] and Hereditary Diffuse Gastric and Lobular Breast Cancer Syndrome (CDH1) [13].