HSPA5 and obesity due to melanocortin 4 receptor deficiency: Recently, we showed that the expression of GRP78 is abundant in adipose tissues, especially in the visceral regions, and augmented by the conditions of older age, obesity, and diabetes; the overexpression of GRP78 in adipocytes was attributed to hyperinsulinemia, which is usually found in older age and obese and diabetic conditions, and is significantly associated with the stress-responsive transcription factor XBP-1s; glucose levels had little impact on the regulation of GRP78 in adipocytes, suggesting that insulin resistance is a major cause of GRP78 overexpression in adipose tissue [12].