SFRP5 and lung cancer: Our present data is in concordance with previous reports showing altered methylation patterns in lung cancer in genes such as PRDM2 [32], RUNX3 [33-38], RARB [37,39-41], SCGB3A1 [42,43], TWIST1 [44], DLC1 [45,46], SFRP4 [36,44], SFRP5 [36,38,44,47], CCND2 [40,41,48,49], BCL2 [50] and TIMP3 [14,46,51].