We tested the basic ability of the CORD assay to detect hypermethylated cancer-derived DNA in comparison with blood-derived DNA by spiking EpiScope methylated HCT116 gDNA (Takara Bio Inc., Japan; control DNA for methylation of RUNX3) into DNA retrieved from leukocyte DNA (control DNA for demethylation of RUNX3) at the following ratios: 100%, 50%, 25%, 12.5%, 6.25%, 3.12%, 1.56%, and 0%. This evidence concerns the gene RUNX3 and cancer.