Representative methylation results in colorectal tumors and normal mucosa. Results of CDKN2A, CRABP1, HOXA9, and RUNX3 in selected samples are shown. Positive controls (POS): NB, normal blood, for the unmethylated reaction and IVD, in vitro methylated DNA, for methylated reaction. Negative controls: dH2O. U: unmethylated alleles, M: methylated alleles. The ladder (left lane) is the EZ Load™ 100 bp Molecular Ruler (BioRad, Hercules, CA, USA).