Acylated and Unacylated Ghrelin Promote Proliferation and Inhibit Apoptosis of Pancreatic β-Cells and Human Islets: Involvement of 3′,5′-Cyclic Adenosine Monophosphate/Protein Kinase A, Extracellular Signal-Regulated Kinase 1/2, and Phosphatidyl Inositol 3-Kinase/Akt SignalingRiccarda Granata, Giampiero Muccioli|Endocrinology|2006Cited by 290