Also, the convincing mechanistic demonstration was performed mostly with cancer cell lines treated with the demethylating agent 5-aza-2′-deoxycytidine (DAC) and contradicts the fact that DKK1 is secreted by many highly proliferative cancer cell lines (Figures 1B, 3G and 4C) and is detected in many breast, kidney and lung cancer specimens. This evidence concerns the gene DKK1 and cancer.