Specifically, when compromised by HFD feeding, mice with ß cell-specific Pdia1 deletion displayed exaggerated glucose intolerance with significant ß cell abnormalities including diminished islet and serum insulin accompanied by an increased proinsulin/insulin ratio in islets and serum (Figure 3), with diminished insulin packaging and storage in secretory granules and a reduced number of insulin secretory granules (Figure 4). This evidence concerns the gene P4HB and Glucose intolerance.