APC and cancer: Indeed, Jin Z and colleagues investigated the status of APC gene promoter methylation in primary BCs and in their noncancerous breast tissue counterparts and found that APC expression was epigenetically downregulated in 36% of tested primary BCs through hypermethylation of its promoter and in none of the noncancerous breast tissue samples tested, strongly indicating that APC promoter CpG island hypermethylation represents a cancer-specific change [36].