PPARD and rectal cancer: This finding is in agreement with the report that PPARβ/δ’s expression was lower in rectal cancers with poor differentiation than in those with better differentiation, and further corroborated previous reports that PPARβ/δ is responsible for the terminal differentiation of multiple type of cells by modulating expression of cell type specific differentiation-related proteins (Tan et al., 2001; Westergaard et al., 2001; Kim et al., 2006; Yang et al., 2010).