DUSP26 (dual specificity phosphatase 26) is a mitochondrial-targeted phosphatase that regulates MAPK signaling pathways through dephosphorylation of multiple substrates including ERK1/2, p38, and JNK 1. The enzyme's catalytic activity depends critically on its N-terminal scaffolding region, which positions the phosphatase-binding loop for substrate engagement 2. Mechanistically, DUSP26 localizes to mitochondrial outer membranes via an N-terminal mitochondrial targeting sequence 3. DUSP26 loss impairs mitochondrial respiration, increases reactive oxygen species production, reduces ATP generation, and compromises mitochondrial dynamics 34. In cardiac tissue, DUSP26 regulates the FAK-ERK signaling pathway to promote mitochondrial fusion and restore metabolic function 4. DUSP26 also antagonizes MDM2-mediated degradation of DPP4 5. DUSP26 exhibits context-dependent disease relevance. In cancer, DUSP26 overexpression suppresses prostate cancer cell proliferation, migration, and invasion through TAK1-mediated inhibition of p38/JNK signaling 1. Conversely, DUSP26 upregulation promotes aortic valve calcification in cardiovascular disease 5. Loss of DUSP26 in neurons increases mitochondrial oxidative stress and p38 activation, leading to dopaminergic neuronal death relevant to Parkinson's disease pathogenesis 3. Clinically, DUSP26 represents a therapeutic target, with DUSP26 silencing showing potential to impede calcific aortic valve disease progression 5, while DUSP26 overexpression or pharmacological activation may benefit diabetic cardiomyopathy and prostate cancer 14.