A lower KRAS and LKB1 (STK11) copy number, along with nodal stage and patient age, predict brain metastasis with good accuracy (area under the ROC curve of 0.832; p < 0.001) in patients with NSCLC.173 Despite these observations, however, KRAS mutations do not significantly affect the prognosis of patients with NSCLC. Here, STK11 is linked to non-small cell lung carcinoma.