Endoplasmic Reticulum is a cellular organelle where membrane and extracellular proteins are folded with the help of chaperons. Insulin is one example of such extracellular proteins. Unfolded Protein Response (UPR) is a cell response to an increased level of unfolded proteins in ER. In pancreatic β-cells failure in UPR leads to accumulation of unfolded insulin in Endoplasmic reticulum and eventual cell death. This is thought to be one of the causes of type two diabetes.