Dual specificity phosphatase 26 (DUSP26, MKP8) is a tyrosine phosphatase that functions to inactivate MAPK1 and MAPK3, which leads to dephosphorylation of heat shock factor protein 4 and a reduction in its DNA-binding activity. DUSP26 inhibits MAP kinase p38 by dephosphorylating it and inhibits p38-mediated apoptosis in anaplastic thyroid cancer cells. DUSP26 can also induce activation of MAP kinase p38 and c-Jun N-terminal kinase (JNK). It is thought to function variably as both a tumor suppressor and an oncogene in glioblastoma, and separately modulates neuronal proliferation. DUSP26 has been found to be upregulated in the hippocampus of Alzheimer's patients. In immunohistochemistry, DUSP26 has highest cytoplasmic positivity in neurons throughout the central nervous system and in skeletal muscle, and is also found at moderate levels in the lung, heart muscle, breast tissue, reproductive tissues, the urinary bladder, tonsils, and at lower levels in a few other tissues. References: J Neurochem. 2016 Jun;137(5):770-81. doi: 10.1111/jnc.13597. Epub 2016 Mar 17, PMID: 26924229;