Identification of YY1 as a potential transcription regulator for FEN1. A. Top 10 hits of the transcription factors (TFs) that were predicted by TF Research Web sites: Match1.0-public, PROMO, and TFSEARCH. B. The oligo probes were designed to cover different regions of the predicted FEN1 promoter. Probes a, b, and c correspond to the region −290 to −230, −150 to −90, and −60 to 0, respectively. C. The silver staining image of oligo-pulled-down assays using HeLa cell extracts. bSNP: probe b with three SNP sites, r: a probe with random DNA sequences. The unique band, which is indicated by a box, was subjected to MS analysis. D. Top 10 hits of the MS analysis of the unique protein band as specified in Panel C.