GAPDH and early-onset autosomal dominant Alzheimer disease: Some of the presently identified proteins have previously been described as brain tumor markers [8], i.e. glyceraldehyde-3-phosphate dehydrogenase (GAPDH), hemoglobin, tubulin beta, HSP 27, manganese superoxide dismutase Mn-SOD, vimentin, albumin, apolipoprotein A-1, ubiquitine carboxyl-terminal hydrolase L1 (UCH-L1) and glial fibrillary acid protein (GFAP), or implicated in neurodegenerative diseases, i.e. UCH-L1 in both Huntington's and Parkinson's diseases, apolipoprotein A-1 and DRP-2 in Alzheimer's disease [8].