LBP and obesity due to melanocortin 4 receptor deficiency: Besides, increase in serum concentration of lipopolysaccharide binding protein (LBP) has been shown to be a risk factor for obesity, type 2 diabetes and related disorders54, 55; here, likely because of the persistent higher food intake after weaning56, 24-week-old NB + A mice tended to have higher serum LBP levels than the control animals (Supplementary Figure S4), indicating the potential of NB + A mice to develop metabolic diseases at an older age.