Induced Pluripotent Stem Cell

Induced Pluripotent Stem Cells, commonly abbreviated as iPS Cells, are a type of stem cells.

This is a generic term for any non-pluripotent stem cell induced by some means, normally genetic, to express certain proteins that appear to resemble pluripotent stem cells.

In June 2007, a research group at Kyoto University found that activation of four specific gene factors (Oct3/4, Sox2, c-Myc, and Klf4) in adult epidermal stem cells subsequently lead to the expression of protein markers (Nanog and Oct4) by these epidermal stem cells that are normally expressed only by pluripotent stem cells. This was independently confirmed by three other research groups in Harvard University, the University of California, and the Whitehead Institute of Massachusetts.

This has been cited as an advancement in stem cell research, as it may be possible to obtain pluripotent stem cells without resorting to embryonic stem cells, which are controversial.

Unfortunately, one of the four gene sequences necessary for pluripotent induction is oncogenic, and 20% of mice implanted with iPS cells developed cancerous teranomas.