AGFG1 and immunodeficiency disease: The importance of Rab pathways for intracellular transport processes becomes apparent by their involvement in a number of diseases, such as immunodeficiencies, neurological disorders, and cancer progression, attributed to dysregulation of Rab protein function (Cheng et al. 2005; Chia and Tang 2009; Mitra et al. 2011; Pan et al. 2016; Tzeng and Wang 2016).