In addition, DKK3 also appears to play a role in chemoresistance, and Ad-REIC/DKK3 mediated downregulation of MDR-1 expression through JNK activation sensitized previously chemoresistant tumor cells to chemotherapy, which supports the applicability of using Ad-REIC/DKK3 in combination with convention chemotherapies in the treatment of drug-resistant cancers (Kawasaki et al., 2009; Hirata et al., 2012). This evidence concerns the gene DKK3 and neoplasm.