Cluster #1 (red), LKB1 activates AMPK and regulates different biological functions (Shaw RJ, Hawley SA, and Woods A et al.); cluster #2 (green), LKB1 is defective in patients with Peutz-Jeghers syndrome (PJS) (Hemminki A and Jenne DE et al.); cluster #3 (blue), LKB1-AMPK pathway suppresses tumor (Shackelford DB and Ji H et al.); and cluster #4 (yellow), LKB1 related signaling pathways (Lizcano JM and Alessi DR et al.)(Table 5). The gene discussed is STK11; the disease is Peutz-Jeghers syndrome.