APP and Alzheimer disease: Some studies elucidated that miR-200a-3p was downregulated in K595N/M596L (APPswe)/presenilin 1 (PS1) deltaE9 (APP/PS1) mice during the progression of AD (Liu et al., 2014), whereas some other experiments showed that in the brain of AD patients and in the hippocampus of APP/PS1 mice, the expression of miR-200a-3p was increased (Lau et al., 2013; Zhang et al., 2017).