PIK3C3 and inflammatory bowel disease: Maintenance of the endocytic pathway by PIK3C3 or PtdIns3P is essential for epithelial cell polarity in Drosophila and Caco-2 organoids [66], and for polarized distribution of cell-junction proteins in intestinal epithelial cells, because the deficiency of pik3c3 causes IBD-like features in zebrafish [67].