To further investigate the effect of PPARβ/δ on the survival of cancer cells in harsh environments, Jeong et al. found that the expression of hypoxia-induced tumor-promoting cytokines IL-2 and VEGF was significantly weakened in PPARδ-deficient HCT116 colon cancer cells; in other words, PPARδ deletion led to colon cancer cells failing to stimulate endothelial cell angiogenesis and macrophage migration. Here, IL2 is linked to colonic neoplasm.