CDKN2A and lung cancer: Though methylation of p16/INK4A is of considerable interest in lung cancer, with methylation frequencies ranging from 17 to 80% in tumor tissue and 0 to 80% in plasma, sputum and bronchoalveolar lavage [11], here we found that p16/INK4A methylation has no sensitivity for the detection of metastasis in lymph node samples from lung cancer patients, though this was not the aim of the study.