MMP9 and pancreatitis: All eight nanobiosensors (arginase, cathepsin B, cathepsin E, MMP1, MMP3, MMP9, neutrophil elastase, and uPA) were used to measure enzymatic activity in serum samples from four different disease groups: localized pancreatic cancer, metastatic pancreatic cancer, pancreatitis, and a ‘healthy’ control.