STK11 and non-small cell lung carcinoma: Evidently adding more complexity to previous findings indicating a proto-oncogenic role of Notch in NSCLC tumors is the recent discovery that Lkb1 deficiency in A549 cells sustains the overexpression of cAMP–regulated transcriptional coactivator 2 (CRTC2), stimulating the upregulation of the oncogene inhibitor of DNA binding 1 (ID1) [118].