Positioned on human chromosome 19p13.3, LKB1 mutations have been linked to hereditary Peutz–Jeghers syndrome (PJS) [21,22] LKB1 has a critical role in activating tuberous sclerosis complex 2 (TSC2), another vital tumor suppressor gene frequently found mutated in a wide array of human cancers [23,24]. The gene discussed is STK11; the disease is cancer.