Children with both asthma and obesity had a distinctive appearance characterized by reduced methylation of the promoter of chemokine ligand type 5 (CCL5), interleukin 2 receptor antagonist (IL2RA), and T-box transcription factor 21 (TBX21) genes involved in Th1 polarization that is observed in obese asthmatics [52]. This evidence concerns the gene TBX21 and obesity due to melanocortin 4 receptor deficiency.