Protein detection by next-generation mass spectrometry (MS) demonstrated relatively high protein levels of APE1 and PARP1 in the cerebellum of both AD and HC, while Polβ was only detected in AD cerebellum, however, at a lower level than APE1 and PARP1 (Fig. 5 and Additional file 1: Figure S1). This evidence concerns the gene PARP1 and Alzheimer disease.