The number of methylated loci tends to increase from non-cancerous mucosa and adenoma to cancer.

• 结直肠癌中检出全部22个位点甲基化,腺瘤-远端粘膜-正常粘膜甲基化位点数递减,分别为18、13和4个(正常粘膜仅N33、SFRP1、MAGEA1和COX2出现甲基化)。