It has been suggested that hypermethylation of the CpG islands in the cyclin D2 promoter is related to the lack of cyclin D2 protein expression in breast cancer (Evron et al, 2001), prostate cancer (Padar et al, 2003) and gastric cancer (Yu et al, 2003), while hypomethylation of the CpG islands is related to the elevated expression of cyclin D2 in gastric cancer (Oshimo et al, 2003). Here, CCND2 is linked to breast cancer.