STK11 and Cowden syndrome 1: Increased risk of endometrial cancer caused by mutation in the phosphatase and tensin homolog (PTEN) gene in Cowden syndrome (CS) is also demonstrated, as well as ovarian, uterine and cervical cancers related to Peutz-Jeghers syndrome (PJS), due to liver kinase b1 (LKB1/STK11) gene mutation.