Inborn errors of myosin 5b (MYO5B), a gene coding for an enterocyte vesicular motor protein that interacts with Rab proteins, lead to microvillus inclusion disease (MVID), characterized by the absence of microvillus formation, which results in severe neonatal secretory diarrhea (Figure 1) [10,51]. Here, AGFG1 is linked to microvillus inclusion disease.