INS and type 2 diabetes mellitus: Low-density lipoprotein (LDL) can promote apoptosis, while high-density lipoprotein (HDL) can block it.129 In addition, the cholesterol homeostasis of β cells is essential for the insulin secretion, as accumulated cholesterol in the plasma membrane resulting in impaired secretion via exocytosis, and reduced cholesterol in insulin granules making them enlarged, also resulting in secretory dysfunction.130,131 Many polymorphisms and mutations in the genes involved in cholesterol homeostasis of β cells are associated with T2D in multiple ethnic populations.129