Generating iPS Cells from MEFS through Forced Expression of Sox-2, Oct-4, c-Myc, and Klf4 6 @0 d* l3 I+ K) `5 G G. Grant Welstead, Tobias Brambrink, Rudolf Jaenisch , F2 ?: d* V/ ]) r" e/ yWhitehead Institute for Biomedical Research, Massachusetts Institute of Technology % M4 n$ Z& T7 M* J$ z 4 g. P4 M" O) C4 K' r