Human fibroblasts can be induced into pluripotent stem cells (iPSCs), but the reprogramming efficiency is quite low. Here, we screened a panel of candidate factors in the presence of OCT4, SOX2, KLF4, and c-MYC in an effort to improve the reprogramming efficiency from human adult fibroblasts. We found that p53 siRNA and UTF1 enhanced the efficiency of iPSC generation up to 100-fold, even when the oncogene c-MYC was removed from the combinations.