NDRG4 and neoplasm: Differences in methodology or sample population may explain the discrepancies in CRC detection rates of methylation markers NDRG4 and VIM. In the present study, centrifugation appeared effective for enrichment of highly fragmented tumor DNA (low-MW), as supernatant samples enabled a more adequate differentiation between disease and healthy controls compared to unfractioned urine that contains both high-MW and low-MW DNA.