STK11 and lung adenocarcinoma: Based on our biochemical data, including the signaling analysis in lung adenocarcinoma A549 cells (Figure 2I and Supplementary Figure 1C), we investigated the possibility that tumor suppressive functions of LKB1 might be partially achieved through its inhibitory effect on BMP signaling, by performing immunohistochemistry on well-annotated human NSCLC surgical specimen.