Taken together our observations of i) the inverse correlation between HES5 and HES6 in cancer cells treated with 5-aza-2′-deoxycytidine, ii) their inverse correlation in tumour-normal comparisons and iii) strong consensus HES5 binding sites at the HES6 gene locus suggests that HES5 may repress HES6 in prostate epithelial cells. This evidence concerns the gene HES6 and neoplasm.