APP and Alzheimer disease: Previous studies on the effect of bexarotene in different mouse models of AD, including APP/PS1, APP/PS1ΔE9, APP/E3 and APP/E4, APP/PS1-21, Tg2576, Tg, and 3xTg-AD mice concluded that this molecule enhanced the cognitive abilities of these animals in different cognitive tests (i.e. the fear conditioning task, nest building, novel object recognition, the Radial-arm Water Maze task (RWM) and the MWM) (Cramer et al., 2012; Fitz et al., 2013; Landreth et al., 2013; Tesseur et al., 2013; Muñoz-Cabrera et al., 2020).