MAPK3 and autism: Zinc is a structural component of zinc-finger proteins and a transcriptional regulator, and influences some candidate genes reported to be associated with the development of autism, such as MTF1 (metal-responsive transcription factor 1), metallothionein, ZnT5 (zinc transporter 5), COMMD1 (COMM domain-containing protein 1), ERK1 (extracellular signal-regulated kinase 1), TrkB (tyrosine-related kinase B), and ProSAP/Shank (proline-rich synapse-associated protein/SH and multiple ankyrin repeat domains) that themselves are involved in zinc signalling and homeostasis [35,36,37,38,39,40].