PARP1 and Alzheimer disease: In addition, it is interesting to remark that we also found an increase in PARP-1 mRNA levels in MCI lymphocytes, but not in AD (Salech et al., 2017), in support of the idea of a protective role of PARP-1, since, the increase in mRNA of PARP-1 would be present at initial stages of cognitive deterioration, but decreases as the disease progresses to AD.