Fig. 6

A brief summary of KLF4, LTR and KRAB-ZFP/TRIM28 regulatory systems in iPSCs, NESCs and ESCs of different vertebrates. Arrows from TFs to LTRs mean direct regulatory relations. Dashed arrow from KLF4 to LTRs of MacERV3 means predicted regulatory relations based on motif analysis with MEME and correlation coefficient between expression levels of KLF4 and these LTRs. “?”: The KRAB-ZFP concordant with TRIM28 in human and mouse iPSC generation and the recruitment of TRIM28 to LTRs of MacERV3 by an unknown KRAB for monkey are still to be verified