BCL2 and pancreatic insulinoma: Hyperglycemia-induced β-cell apoptosis has been extensively studied on the balance of proapoptotic Bcl-2 proteins (Bad, Bid, Bik, and Bax) and antiapoptotic Bcl family (Bcl-2 and Bcl-xL) toward apoptosis in vitro isolated islets and insulinoma cell culture.