DKK3 and cancer: Ad-REIC/DKK3 has been used with success in preclinical studies demonstrating robust anti-tumor effects including induction of cancer cell specific apoptosis and inhibition of metastatic disease (Abarzua et al., 2005; Edamura et al., 2007; Kawasaki et al., 2009; Sakaguchi et al., 2009; Than et al., 2011), and is currently in clinical trials for use in prostate cancer (see footnote 3; NCT01197209).