In keeping with the nature of defective recycling in MVID, small subapical endosomes containing apical membrane components such as villin, the Na+/H+ exchanger-3 (NHE3), and organized microvilli are the histopathologic hallmark of the disease (Ruemmele et al. 2006; Knowles et al. 2014). Here, SLC9A3 is linked to microvillus inclusion disease.