Apart from the aforementioned changes, obesity also activates and upregulates intracellular pathways (signal transducer and activator of transcription 3 (STAT3), nuclear factor kappa-light-chain-enhancer of activated B-cells (NF-κB), COX-2) that are responsible for the aggravation of inflammation and cellular proliferation but also for blocking the apoptosis [105,106]. This evidence concerns the gene STAT3 and obesity due to melanocortin 4 receptor deficiency.