Originally identified as a novel TSG by Tsuji et al. (2000) using an in vitro transformation model of normal human fibroblasts, reduced DKK3 expression was subsequently observed in cell lines and tumors of several different cancer types including liver, lung, prostate, breast, osteosarcoma, and leukemia (Tsuji et al., 2000; Nozaki et al., 2001; Hsieh et al., 2004; Kurose et al., 2004; Roman-Gomez et al., 2004; Abarzua et al., 2005; Tanimoto et al., 2007; Mizobuchi et al., 2008; Veeck et al., 2008; Yue et al., 2008; Yu et al., 2009; Dellinger et al., 2012). The gene discussed is DKK3; the disease is leukemia.