Indeed, it has been shown that DNMTi treatment also potentiates promotor demethylation‐mediated activation of several known prometastatic genes [urokinase plasminogen activator (PLAU), C‐X‐C motif chemokine receptor 4 (CXCR4), heparanase (HPSE)] in less aggressive MCF‐7 and ZR‐75‐1 breast cancer cells which facilitates their transformation to become more aggressive tumour cells.14 This evidence concerns the gene PLAU and breast cancer.