PPIF and Cognitive impairment: Previous studies have shown that CypD may be associated with AD neuropathogenesis (Wang et al., 2009; Zhu et al., 2013; Adiele and Adiele, 2016) and CypD deficiency may have a protective effect on mitochondrial dysfunction and cognitive impairment in old AD mice (Du et al., 2008, 2011, 2014).