Several studies have suggested the presence of a gene that is associated with PJS other than STK11. In an investigation of 21 PJS patients from 13 families, Papp et al identified that 8 (62%) of the 13 cases of PJS had familial medical histories and that the remaining five cases (38%) were due to de novo mutations (12). Here, STK11 is linked to Peutz-Jeghers syndrome.