The nuclear envelope membrane is the double-membrane structure surrounding the nucleus of eukaryotic cells, which serves as the boundary between the nucleoplasm and the cytoplasm. It regulates the movement of materials into and out of the nucleus, protecting the genetic information encoded within. The nuclear envelope is composed of two lipid bilayers, forming an outer and inner nuclear membrane. These membranes are continuous with the endoplasmic reticulum, allowing for direct communication and transport between the nuclear and cytoplasmic compartments. They are also studded with nuclear pores, large complexes of proteins that facilitate selective transport of molecules across the nuclear envelope. In addition to acting as a barrier, the nuclear envelope provides structural support and participates in important cellular processes such as nuclear assembly, chromatin organization, and gene expression.