PPARD and cancer: In cancers, ligand activation of PPARβ has been shown to attenuate colon carcinogenesis (Harman et al, 2004; Marin et al, 2006), and decreased PPARβ expression has been displayed by microarray analysis in high-grade tumour samples compared to control tissues, suggesting that decreased expression of PPARβ may be linked to an increase in the loss of differentiation required for the progression of colon malignancies (Notterman et al, 2001).