We quantified mRNA abundance of AhR, CYP1A1 (as a marker of AhR activation) and TNF-α (as a marker of inflammation) in adipose tissue of obese mice experiencing weight loss (mice were exposed to PCB-77 during the weight-gain phase of diet-induced obesity). Here, CYP1A1 is linked to obesity due to melanocortin 4 receptor deficiency.