Colonic GZMK+ (granzyme K) CD8+ Tem cells were clonally expanded in a pediatric IBD cohort with active disease. Furthermore, colonic ITGAE (CD103) CD8+ Trm and ENTPD1 (CD39) CD8+ Trm cells were decreased in pediatric IBD compared to controls. Here, ENTPD1 is linked to inflammatory bowel disease.