TFAP2C and autism: The MC3R (melanocortin 3 receptor) gene is known to play a role in obesity while the CDH4 is a member of the cadherin gene family mediating calcium-dependent cell-cell adhesion and plays a role in autism. TFAP2C modulates the transcriptional activity of vitamin A and target genes via the retinoic receptors and is expressed in migrating neural crest cells in the developing embryo [33].