The effect of over-expressing PPARβ/δ and/or ligand activation of PPARβ/δ on tumor-marker proteins. Representative western blot analysis of xenografts from (A) MDA-MB-231-MigR1 (MigR1), MDA-MB-231-hPPARβ/δ (hPPARβ/δ) cells in host mice treated with or without GW0742 or (B) MCF7-MigR1 (MigR1), MCF7-hPPARβ/δ (hPPARβ/δ) cells in host mice treated with or without GW0742. Expression of PPARβ/δ, p65, PCNA, FABP5 and CRABP-II proteins were examined. Signals for each protein were normalized to that of ACTIN and represent the mean ± S.E.M.. Values represent the mean ± S.E.M.. Values with different letters are significantly different, P ≤ 0.05.