CRABP1 and obesity due to melanocortin 4 receptor deficiency: Through mining human patient data sets, we found patients of inflammatory diseases with downregulated CRABP1 expression (Supplementary Table 1), including multiple sclerosis [51, 52], Crohn’s Disease [53, 54], Psoriasis [55, 56], and HIV-therapy induced metabolic syndrome [57], etc. Importantly, patients of these diseases all have significantly reduced CRABP1 expression and are associated with abnormality in adipose tissue/obesity.