Cell polarity is a central feature of most if not all cells across species. Polarity can be understood as the unequal distribution of molecules, organelles and other cellular features allowing cells to organise functions and physiological outputs according to this axis of polarisation. For instance, epithelial cells secrete and absorb molecules, migratory cells crawl, and neurons orchestrate information flow according to their axis of polarisation.
The epigenetic mark of DNA methylation is established by DNMT (DNA methyltransferase) enzymes and has been shown to correlate with transcriptional states and influence cell identity and tumorigenesis in mammalian cells.
The human genome is spatially organised at multiple levels within the nucleus during interphase. Chromatin loops are basic units of genome organisation  – they span tens to hundreds kilobases of DNA and often facilitate enhancer–promoter interaction for gene expression. The formation of a chromatin loop relies on cohesins and the CCCTC-binding factor (CTCF). The 4C and Hi-C analyses revealed formation of chromatin loops genome-wide. However, it is still unclear how the conformations of chromatin loops change over time and what molecular mechanisms regulate such changes.