Because obesity is closely associated with a state of chronic, low-grade inflammation in adipose tissues22, the expression of intercellular adhesion molecule 1 (ICAM-1) but not adiponectin was higher in WAT of ATF3−/− than wild-type mice (Fig. 3b, Supplementary Fig. 1d). Here, ICAM1 is linked to obesity due to melanocortin 4 receptor deficiency.