For example, xanthine oxidoreductase, a key enzyme in the degradation of DNA and RNA, is associated with histological grade of differentiation and severity of disease in colorectal cancer (Linder et al., 2009), as well as the migratory activity of human breast cancer cells (Linder et al., 2005; Fini et al., 2008). Here, XDH is linked to breast carcinoma.