We assessed amounts of APP holoprotein in postmortem cortex by probing blots with an antibody specific for C-terminal APP (6E10), which yielded two main bands at 106 and 113 kDa and a faint band at 130 kDa in late-stage AD brain, together characteristic of the three major APP isoforms found in human brain [14, 54], Fig. 2a). This evidence concerns the gene APP and Alzheimer disease.