YAP1 and colitis: Some studies have shown that prostaglandin E2 (PGE-2) signaling increases the expression and transcriptional activity of YAP1, resulting in the increased expression of cyclooxygenase-2 and prostaglandin E2 receptor 4, activating a positive feedback loop and promoting regeneration of colonic epithelial cells in colitis mice (Kim et al., 2017).