MST1 and diabetes mellitus: Since the discovery of highly activated serine/threonine kinase Mammalian Sterile 20-like kinase 1 (MST1), a core kinase in the Hippo signaling pathway, during pancreatic β-cell failure in the pancreas and diabetes progression [1], MST1 targeted therapies were designed to protect β-cells and prevent diabetic complications, such as nephropathy and cardiomyopathy [2–6].