DUSP23 is a dual-specificity protein phosphatase that dephosphorylates proteins on tyrosine and serine/threonine residues 1. In vitro, DUSP23 dephosphorylates p44-ERK1 but exhibits substrate selectivity, failing to dephosphorylate p38 and p54SAPKbeta 1. The enzyme localizes to the cytoplasm and contains a dual-specificity phosphatase catalytic domain 1. Mechanistically, DUSP23 coordinates post-translational modifications of target proteins. In placental development, DUSP23 interacts with the transcription factor GCM1 and reverses GSK-3β-mediated phosphorylation, promoting GCM1 stabilization and activation 2. In kidney fibrosis, DUSP23 mediates dephosphorylation of phospho-SMAD3, antagonizing the EZH2/histone methylation pathway that suppresses Dusp23 expression 3. DISEASE RELEVANCE: DUSP23 overexpression associates with systemic lupus erythematosus, with elevated levels in patient CD4+ T cells correlating with increased DNMT expression 45. High DUSP23 expression serves as a poor prognostic indicator in acute myeloid leukemia and non-small cell lung cancer 67, with genome-wide association studies identifying DUSP23 locus variants associated with AML risk 8. DUSP23 promotes cancer cell proliferation and invasion through MAPK pathway regulation 67.