Pluripotent stem cells induced from adult neural stem cells by reprogramming with two factors

The process of reprogramming somatic cells, the 'ordinary' cells that make up most body tissues, to become induced pluripotent stem cells (iPS cells) involves the expression of four transcription factors — Oct4, Sox2, c-Myc and Klf4. With a view to making the procedure simpler and potentially safer in clinical applications, efforts to reduce the number of transgenes required, and to eliminate the need for the oncogene c-Myc, are under way. Kim et al. now show that just two endogenous factors — Oct4 plus either Klf4 or c-Myc — are sufficient to generate iPS cells from adult mouse neural stem cells. This is possible because these neural cells express higher endogenous levels of Sox2 and c-Myc than embryonic stem cells, pointing to somatic cells with a suitable natural complement of transcription factors as a potentially useful starting point for iPS cell production.