While most experimental studies on PGRN in brain have employed animal models of FTD with single mutation or GRN gene knockout, the number of studies relating to PGRN and AD are limited, but one feature observed in studies of AD transgenic mice and human brain samples was that PGRN accumulated around Aβ plaques [19, 31–34]. The gene discussed is GRN; the disease is frontotemporal dementia.