As a result, our screening uncovered some well-known methylation markers, some of which have tumor suppressor activity: CDKN2A, MGMT, GATA4, HOXA7, HOXA9, RUNX3, SFRP1. Most of the identified genes are novel methylation markers for NSCLC, although some of these have been described as methylated in other cancers. This evidence concerns the gene SFRP1 and non-small cell lung carcinoma.