In the present study, normal aging and AD pathogenesis were associated with a decrease in PKCε, MnSOD, and VEGF, possibly due to a prolonged and significant increase in O2•– that favors reaction with the free radical nitric oxide (NO⋅) to form peroxynitrite (ONO2–), a powerful oxidant that damages DNA, RNA, and proteins, including PKC (Maher, 2001). Here, SOD2 is linked to Alzheimer disease.