VIPAS39 and cholestasis: The discovery that mutations in VPS33B or VPS16B (VIPAS39, VIPAR, SPE-39) are responsible for arthrogryposis, renal dysfunction, and cholestasis (ARC) syndrome provided the first evidence that the biogenesis of α-granules depends on membrane trafficking machinery (Urban et al., 2012; Lo et al., 2005; Gissen et al., 2004).