For long, scientists have been puzzled by the fact that long strands of DNA apparently have no real function. What is more, these strands are identical across several animals, adding to the conundrum. Now a study shows that these might not merely have a function but that they might play an essential role in the development of the brain. Mice in which four such regions had been knocked out outwardly looked normal but the brains showed abnormalities when dissected. The mice without specific strands showed similarities to Alzheimer’s while others showed abnormalities in the forebrain – involved in memory formation.