In addition, PGI2 is required to prevent penetrating ulcers after colonic mucosal injury.52 PGI2 can inhibit intestinal epithelial permeability and apoptosis, alleviate colitis and prevent penetrating ulcers, probably through stimulating VEGF-dependent angiogenesis.30 Given the increased expression of PTGIR in fibrostenotic tissues and the multiple functions of PTGIR agonism in antifibrosis, anti-inflammatory, and mucosal healing, assessing the antifibrotic effects of PGI2 analogs in preventing intestinal fibrosis in clinical trials is promising. The gene discussed is PTGIR; the disease is colitis.