DNA structuring proteins such as CTCF facilitate DNA loop formation and are presumed to be among the major determinants of eukaryotic genome structure. Recent studies, including Rowley et al. (2017), suggest that gene activation and repression play fundamentally important roles in structuring the genome independently of CTCF.
Hnisz, D., & Young, R. A. (2017, September 7). New Insights into Genome Structure: Genes of a Feather Stick Together. Molecular Cell. Cell Press. https://doi.org/10.1016/j.molcel.2017.08.023