Such animals still had normal circulating thyroid hormone and TSH levels (Figure 1B) and normal thyroid histology (Figure 1C) but showed an increase of IRE1α and OS9 (Figure 1D, quantified in graph) that is typical of ERAD deficiency (35), along with a small increase of phosphorylated eIF2α — but without statistical increase of BiP, ERdj6 (Figure 1D), or spliced XBP1 (Figure 1E) — plus moderate swelling of the ER as detected by electron microscopy (Figure 1F). Here, ERN1 is linked to hyperinsulinemic hypoglycemia, familial, 4.