of ndrg4 protein while no promoter methylation was observed this observation suggests that other mechanisms might lead to ndrg4 inactivation no mutations were found indicating that mutational inactivation of the ndrg4 gene might not play a mayor role in crc our results confirmed previous data on ndrg4 mutation studies sjoblom jones et al 2006 however loh at 16q is seen in about 30 of the crc cases frequent loh of 16q had previously been described in a wide variety of solid tumor types as breast rakha green et al 2006 liver sakai nagahara et al 1992 bando nagai et al 2000 prostate elo harkonen et al 1997 ovarian kawakami staub et al 1999 and wilms 39 tumors mason goodfellow et al 2000 but until now it has not been described in crc because ndrg4 is downregulated in most of the colon cancer cells compared to normal colonic epithelial cells we hypotheses that ndrg4 has a tumor suppressor function in cancer in conclusion we are the first group who described a role for ndrg4 in cancer and our data indicate that ndrg4 is a potential novel marker for crc with a very high sensitivity and specificity of 76 and 100 respectively although the sensitivity and specificity of ndrg4 as a marker alone is already very high the diagnostic accuracy of ndrg4 may be enhanced by the addition of other markers analyzed in patients with crc as well this may.