When methylation values were compared within individual pairs of PN and PT samples, significantly higher methylation levels of PAPSS2 TUBG2, NTRK2, and SFRP4 were found in 60% (18/30), 50% (15/30), 30% (9/30), and 36% (11/30), respectively, in PN than in corresponding tumor samples (PT). The gene discussed is SFRP4; the disease is neoplasm.