XBP1 and obesity due to melanocortin 4 receptor deficiency: Our present study systematically demonstrated that in Chinese male adults the metabolic alterations in the transition from lean to obesity were accompanied by increased expression of stress kinases, as well as significant increase in the mRNA expression of ER stress markers (i.e. GRP78, CHOP and XBP-1), inflammatory markers (i.e.TLR2, TLR4, and CCR2) and AD markers (i.e. APP, PS1 and PS2).