In eukaryotes, the phosphorylation and dephosphorylation of proteins on serine and threonine residues is an essential means of regulating a broad range of cellular functions, including division, homeostasis and apoptosis. A group of proteins that are intimately involved in this process are the protein phosphatases. Dullard, also known as NET56, is a 244 amino acid single-pass membrane protein that localizes to both the nucleus and the endoplasmic reticulum and contains one FCP1 homology domain. Functioning as a serine/threonine phosphatase, Dullard catalyses the dephosphorylation of target proteins and is thought to be required for proper nuclear membrane morphology. Human Dullard shares 92% sequence identity with its zebrafish counterpart, suggesting a conserved role between species.