IL4 and obesity due to melanocortin 4 receptor deficiency: Indeed, in addition to the progressive increase of miR-34a in mouse epididymal white adipose tissue upon administration of high-fat diet, it has also been demonstrated that in obesity the hypertrophic adipocytes’ exosomal miR-34a suppresses the IL4-induced polarization of macrophages into anti-inflammatory M2 phenotype, by targeting the transcription factor KLF4 [89].