We immunostained our NL (Fig. 7A), M (Fig. 7B), and AD (Fig. 7C) case patients for the cell cycle protein marker cyclin A. As reported previously (Busser et al., 1998; Yang et al., 2006), this marker is elevated in a disease-specific manner during the progression of AD and, like other cyclins, can appear in either the nucleus or, more infrequently, the cytoplasm. This evidence concerns the gene PCNA and Alzheimer disease.