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. This evidence concerns the gene AP3B1 and pulmonary fibrosis.