In a more detailed analysis, the SHOX2, RASSF1A and, PTGER4 methylation panel showed 89.0% in adenocarcinoma, 87.5% sensitivity in squamous cell carcinoma, 85.7% in small cell lung cancer and 77.8% sensitivity in other lung cancer, respectively, which means the SHOX2, RASSF1A and PTGER4 methylation panel in plasma is a noninvasive biomarker with wide application in almost all histological subtypes of lung cancer. This evidence concerns the gene PTGER4 and squamous cell carcinoma.