The amyloid beta protein precursor or proteinase nexin II from mouse is closer related to its human homolog than previously reported.

The cDNA sequence for amyloid precursor protein and the two alternatively spliced forms were determined. Seven nucleotide differences resulting in six amino acid differences compared to the previously published mouse sequence were found. Moreover, the 3' non-coding end was completely different. Part of these findings were confirmed in three different mouse strains. The resulting mouse cDNA resembles the human APP more closely than originally reported.