Induced pluripotent stem cells are stem cells made directly from somatic cells. Somatic cells, or differentiated cells, are reprogrammed into iPS by introducing four genes that encode four transcription factors (OCT4, SOX2, KLF4 and c-MYC). These genes are active in pluripotent stem cells but are largely dormant in differentiated cells. Scientists are still elucidating the exact mechanisms of gene reprogramming to generate iPS.

Induced pluripotent stem cells have revolutionized the field of stem cell research and have their own advantages and disadvantages, compared to embryonic stem cells.