Moreover, beside the recurrent CDC73 promoter hypermethylation discussed above, altered methylation levels of the adenomatous polyposis coli (APC) promoter 1A region is recurrently seen in parathyroid tumors, although the APC mRNA expression seem to be retained by an unmethylated 1B promoter region [75, 116]. Here, CDC73 is linked to tumor of parathyroid gland.