Instead of using one or more transcription factors, researchers have used small molecule chemicals to generate neurons from skin cells and have published 2 papers in the journal Cell Stem Cell.
In the first paper, scientists disrupted the fibroblast genes and induced neural genes and added small molecules to convert mouse fibroblasts to neurons. In the 2nd paper, skin cells from Alzheimers patients were treated with small molecules to generate neurons.
http://www.cell.com/cell-stem-cell/abstract/S1934-5909(15)00263-5