Junction, a term in telecommunications, refers to a device installed between cables, featuring certain insulation and sealing properties to allow for continuous operation of two or more cables. In genetic engineering, it is a sequence that enables two DNA molecules or the ends of a single DNA molecule to be paired and covalently linked by an enzyme. Currently, artificial hexamer junctions (containing a specific enzyme's切口) are commonly used, and multiple hexamer junctions can be connected to form a polypoly junction.inker)。