Multiple ATFs composed of three zinc finger proteins linked together can each activate genes that eventually lead to the production of the Oct4 transcription factor in the cell, causing the cell to reprogram to an induced pluripotent state without the addition of external Oct4 transcription factors.
Multiple zinc finger proteins linked together form a complex called an ATF that can activate genes leading to the production of the Oct4 transcription factor, which in turn induces reprogramming of cells into an induced pluripotent state without needing external Oct4 factors.