High-frequency methylation profiles have been reported for several cancer-specific genes, including SOX17, TAC1, HOXA7, CDO1, HOXA9, and ZFP42, in both preoperative plasma and sputum samples from lymph node-negative stage I and IIA non-small cell lung cancer (NSCLC) patients [103]. The gene discussed is HOXA9; the disease is non-small cell lung carcinoma.