For example, in the adipose tissue of Zip14-KO mice, hypertrophy together with enhanced proinflammatory signaling is observed through activation of nuclear factor-kappaB (NF-κB) and the Janus-activating kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathway, and this might contribute to obesity-induced insulin resistance [62]. This evidence concerns the gene STAT3 and obesity due to melanocortin 4 receptor deficiency.