OCLN and cancer: Maintain a high rate of intestinal epithelial cell proliferation.Dysregulated polyamine metabolism may promote the growth of cancer.Promote the production of intercellular junction proteins (occludin, zonula occludens-1 (ZO-1), and E-cadherin) to improve intestinal barrier integrity and function.Spermine suppresses pro-inflammatory M1 macrophage activation and promotes intestinal and systemic adaptive immune system development.