PPAR beta/delta activation or overexpression may upregulate the expression of its various downstream signal molecules involved in tumor angiogenesis including proangiogenic factors (such as VEGF, PDGF, and FGF), proinvasive matrix-degrading enzymes (such as MMP9), proinflammatory mediators (such as COX2), and cytokines and chemokines (such as IL1 and CXCL8), even some of which have been further identified as PPAR beta/delta direct target genes. This evidence concerns the gene CXCL8 and neoplasm.