New preliminary research out of UC-Irvine shows the discovery of a creator gene responsible for differentiating cells into brain tissue. This is a key element in creating a stem cell line of cells that could be used to regenerate brain tissue in patients with diseases like Alzheimer's.
These genes are highly selective, and likely only operate in a small window of time during early development. It would be interesting to see what a homolog gene does in other organisms, as it might provide insight as to how we got our big juicy think-globs. Mmmmm, thinky.