CCN2 and Peritoneal Fibrosis: Intracellular hypoxia upregulates the hypoxia-inducible factor-1 gene, which stimulates the glucose transporter-1 (GLUT-1) gene and many profibrotic genes (e.g., TGF-β, VEGF, PAI-1, and CTGF), promoting the development of peritoneal fibrosis.