Several point site mutations in LKB1 kinase domain, such as D176, K78 and L67 residues, have been reported to be responsible for loss of function of LKB1, resulting in Peutz-Jeghers syndrome, an autosomal-dominant polyposis with multiple organ malignancies disorder 21. The gene discussed is STK11; the disease is Peutz-Jeghers syndrome.