(A) Representative hematoxylin and eosin (HE) staining of ileum. Paneth cells with typical eosinophilic granules (black arrows) on HE-stained sections at the base of crypts in Villin-Cre and COPS8-lox alleles expressing (COPS8fl/fl ), but not COPS8 knockout (KO) (COPS8ΔIEC) epithelium. Scale bar 50 μm, n=7 biological replicate per genotype. 