Recently, Zohny and colleagues have proposed as diagnostic markers of breast cancer the expression levels of p21CIP1/Waf1 and p57Kip2 combined with the promoter methylation of CDKN1C, since they found a silenced expression of the two CKIs and a hypermethylation of CDKN1C promoter in more than 50% of the breast cancer specimens analyzed, together with no hypermethylation at promoter of p21CIP1/Waf1-coding gene [159]. Here, CDKN1A is linked to breast cancer.