Today, Cowden Syndrome (CS), Lhermitee-Duclos disease, and Bannayan-Riley-Ruvalcaba-Syndrom (BRRS) belong to the so-called PTENopathies or PTEN hamartoma tumor syndromes, which are a spectrum of diseases induced by PTEN loss-of-function mutations. Here, PTEN is linked to Bannayan-Riley-Ruvalcaba syndrome.