GCG and Insulin resistance: The upregulation of GLP-1 receptor transcripts with no significant changes in protein abundance in untreated diabetics is suggestive of compensatory upregulation of incretin signaling at the transcript level in the liver to counteract insulin resistance, and the downregulation of GLUT-1 and GLUT-2 transcripts in diabetics is suggestive of impaired glucose uptake in the liver.