The role and molecular mechanisms of exosomes carrying proteins related to the brain diseases [amyloid precursor protein (APP), α-synuclein (α-syn), mHtt, PrPsc] have been emphatically explored (Hartmann et al., 2017; Leblanc et al., 2017; Wang J. K. T. et al., 2017; Hill, 2019; Li B. et al., 2020; Pan et al., 2020; Perez-Gonzalez et al., 2020; Singh and Muqit, 2020; Tsunemi et al., 2020, 2021; Ananbeh et al., 2021; Soares Martins et al., 2021a). Here, APP is linked to brain disorder.