Previous studies showed that overexpression of REIC/Dkk-3 using adenoviral or plasmid vectors induces apoptosis in various cancer cell lines, but not in normal cells, via c-Jun-NH2-terminal kinase (JNK) and c-Jun activation, and endoplasmic reticulum (ER) stress signalling [7, 10–13]. The gene discussed is DKK3; the disease is cancer.