This path to creating pluripotent stem cells is becoming simpler: "the introduction of four ingredients could transform differentiated cells taken from adult mice into 'induced pluripotent stem cells' (iPS) with the physical, growth, and genetic characteristics typical of embryonic stem cells ... Subsequent studies found that the four-ingredient recipe could in some cases be pared down to just two or three essential ingredients, [and] Now we've come down to just one that is sufficient. In terms of the biology, it's really quite amazing. ... adult cells could be reprogrammed by adding four factors – specifically Oct4, Sox2, Klf4, and c-Myc. Recently, [researchers] demonstrated that Oct4 and Klf4 are sufficient to induce pluripotency in neural stem cells. By omitting Klf4 in the new study, they have now established that Oct4 is the 'driving force' behind the conversion of the neural stem cells into iPS cells. The lone transcription factor is not only essential, but it is also sufficient to make neural stem cells pluripotent." Simpler means cheaper, and cheaper means a broader range of applications in further development.