RARB and breast cancer: In the same context, Lee and Zhu [281] demonstrated that treatment of human breast cancer cells with commercial caffeic acid inhibited DNA methylation via methylation of the promoter region of the RARβ gene and its unmethylation status, but without any changes in the global DNA methylation, leading the authors to suggest that the observed changes may be gene-specific and were not sufficient to be detected by the experiment used [281].