Apart from melanocytes, AP3B1 defects include prolonged bleeding due to the disrupted transport of the von Willebrand factor (VWF) in Weibel–Palade bodies (WPBs) [8], immunodeficiency, and pulmonary fibrosis due to defects in lamellar body biogenesis in type II pneumocytes. Here, VWF is linked to immunodeficiency disease.