“…The expression of ‘self’ peptides on these MHC molecules makes EVs immunologically inert and, therefore, capable of being widely distributed within the body. Their presence has been reported in all body fluids including blood, urine, cerebrospinal fluid, salvia, breast milk, semen and tears ( Pisitkun et al 2004 , Keller et al 2007 , Mathivanan et al 2010 , Baranyai et al 2015 , Gui et al 2015 , Höög & Lötvall 2015 , Riches et al 2016 ). It is through their widespread distribution and evasion of the immune system which means they are capable of reaching tissues, remote from their cell of origin to mediate their effects.…”