Ligand activation of PPAR-δ increases breast cancer cell proliferation and promotes mammary gland cancer development (27-29); polyunsaturated fatty acids and their related metabolites modulate PPAR-δ expression and function (19); therefore, the possible association of 13(S)-HODE with PPAR-δ in the breast cancer cells has been evaluated in this study and it has been demonstrated that 13(S)-HODE significantly reduces PPAR-δ expression and activity in colorectal cancer (21). The gene discussed is PPARD; the disease is breast carcinoma.