Title: Theoretical analysis of the role of chromatin interactions in long-range action of enhancers and insulators Authors: Swagatam Mukhopadhyay, Paul Schedl, Vasily M. Studitsky, and Anirvan M. Sengupta Presenter: Saeed Saberi The 3D configuration of chromosomes is highly regulated in eukaryotes, via different proteins binding to the linear chromosome. These proteins interact with each other in order to make highly interacting domains of size 100kb-1Mb. The resulting spatial patterning affects the probability of physical contacts between different gene promoters and enhancers and consequently changes the expression of associated genes. The paper by S. Mukhopadhyay et al. uses Monte-Carlo simulations to address two problems: First, the very long scale interactions observed in distal promoters-enhancers seem to be inconsistent with Gaussian polymer models. Second, this paper shows how interactions between different chromatin proteins form chromosomal domains and consequently favour intra-domain interactions. This will result in over-expression of genes whose enhancer and promoters belong to the same domain while reducing the expression of others.