The cellular heterogeneity revealed by scRNA-seq analysis explains the diagnostic power of our four-gene panel, as each gene captures distinct aspects of IBD pathophysiology: metabolic dysregulation (PDK2), epithelial barrier dysfunction (UGT2A3), cell cycle perturbation (CDC14A), and extracellular matrix remodeling (CHAD). Here, UGT2A3 is linked to inflammatory bowel disease.