The nucleus is a specialized organelle found in eukaryotic cells, which houses the cell's genetic material in the form of chromosomes. It is surrounded by a double membrane called the nuclear envelope, which contains pores that allow for the transport of molecules in and out of the nucleus. The nucleus plays a critical role in controlling gene expression, DNA replication, and cell division. Research in this area often focuses on understanding the structure, function, and regulation of the nucleus, as well as the mechanisms underlying diseases such as cancer that involve nuclear processes.