In a murine model study comparing obese IFN-γ-knockout mice vs. mice with diet-induced obesity, the roles of IFN-γ were demonstrated in the regulation of the AT structure (enlarged adipocyte and leukocytic infiltration), M2 shift of AT macrophage phenotype, cytokine expression (increased TNF-α and decreased IL-10 transcription levels), and reduced insulin sensitivity in mice with diet-induced obesity [47]. This evidence concerns the gene INS and obesity due to melanocortin 4 receptor deficiency.