STK11 and osteosarcoma: LIP1 binds to LKB1 and anchors LKB1 to cytoplasm. Endogenous DAP3 could interact with LKB1 in osteosarcoma cells. Expression of LKB1 induced apoptosis and co-expression of LKB1 with DAP3 strongly induced apoptosis in osteosarcoma cells.