A single cell contains 2-3 meters of DNA, meaning that the only way to store it is to package it into tight coils. The solution is chromatin: a complex of DNA wrapped around proteins called histones. In the 3D space, this complex is progressively folded into a multi-layered organization composed of loops, domains, and compartments, which makes up what we know as chromosomes. The organization of chromatin is closely linked to gene expression and the cell’s proper function, so any problems in chromatin structure can have detrimental effects, including the development of cancer.