OGG1 and breast cancer: However, reduced OGG1 protein, and thus activity, has been observed in prostate cancer cells (Trzeciak et al., 2004), and reduced OGG1 has also been associated with increased risk of head and neck squamous cell carcinoma (Paz-Elizur et al., 2006; Kumar et al., 2012) and with an aggressive form of breast cancer (Karihtala et al., 2012) observed utilizing patient tumor samples.