-Upregulated the expression of opioid binding protein/cell adhesion molecule (OPCML) in breast cancer cells-Activated the OPCML by reducing intracellular methylation levels-Downregulated the intracellular methylation levels by decreasing Sp1 and NF-κB activities-Affected the expression of DNMT1 and OPCML by downregulating Sp1 activity-Inhibited the proliferation and induced the apoptosis of BT474 and MCF-7 cells⇒ Luteolin inhibits the growth of breast cancer cells by decreasing methylation and upregulating the expression of the OPCML gene. This evidence concerns the gene NFKB1 and breast cancer.