DUSP23, also known as low molecular mass dual specificity phosphatase 3(LDP-3), belongs to the protein-tyrosine phosphatase family. This protein is a protein phosphatase that mediates dephosphorylation of proteins phosphorylated on Tyr and Ser/Thr residues. In vitro, it can dephosphorylate p44-ERK1 (MAPK3) but not p54 SAPK-beta (MAPK10) in vitro. This protein able to enhance activation of JNK and p38(MAPK14). Recombinant human DUSP23 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.