GCG and metabolic disease: The title of this landmark paper was “Preproglucagon Gene Expression in Pancreas and Intestine at the Level of Posttranslational Processing.” However, the key finding was, “It appears that GLP-I (1-37) may be a 'prohormone' or precursor for GLP-1 (7-37).” This rather understated conclusion encapsulates the key discovery that ultimately made the revolutionary new treatments for metabolic disease possible.