INS and pancreatic insulinoma: reported that the VPS41 subunit of the HOPS complex is involved in the regulated secretory process of ESGs (Asensio et al. 2013), and Burns et al. (2021) reported that VPS41 expression requires the exocytosis of insulin from pancreatic β-cells based on the use of the rat insulinoma cell line INS-1 and conditional gene knockout mice.