OCLN and Fabry disease: Also, the FD mice showed lower levels of epithelial tight junction proteins, occludin, and zonula occludens-1 (ZO-1) (both p < 0.05, Fig. 4F) and higher levels of fecal albumin and serum LPS (both p < 0.05, Fig. 4G, H), indicating impaired epithelial barrier integrity and increased gut permeability.