GAPDH is a glycolytic enzyme which plays a key role in energy production, and has also been implicated in numerous cellular processes. GAPDH is a homotetramer molecule consisting of four 36 kDa subunits, constitutively expressed in most cells and tissues, and is responsible for the generation of energy during carbohydrate metabolism, catalysing the reversible oxidative phosphorylation of glyceraldehyde-3-phosphate. The role of GAPDH as a multifunctional protein has emerged from many studies, confirming its involvement in critical nuclear pathways, apoptosis, membrane transport and fusion, DNA replication and repair and phosphotransferase activity. Furthermore, the ability of GAPDH to bind with high affinity to ß-amyloid precursor protein (Alzheimer's disease) and selectively with CAG mutated proteins, including huntingtin (Huntingdon's disease) and the androgen receptor (spinobulbar muscular atrophy), has focused many studies towards the role of GAPDH in the pathogenesis of neurodegenerative diseases (1).Synonyms: CDABP0047, GAPD, Glyceraldehyde-3-Phosphate Dehydrogenase