NSD3, or Nuclear Speckle Domain 3, is a protein that plays a crucial role in the regulation of gene expression. It is part of the nuclear speckle structures within the cell nucleus, which are involved in the processing of RNA and the assembly of ribosomes. Research indicates that NSD3 may also be linked to various cellular processes, including cell growth and differentiation. Abnormalities in NSD3 expression have been associated with certain diseases, including some types of cancer, highlighting its importance in maintaining normal cellular functions.