SFRP1 and cancer: 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.