Fig. 1.

EV bulk packaging. In traditional cytokine-mediated cell signaling the cell secretes a cytokine that can only activate downstream signaling in cells expressing its corresponding receptor, thus linking signal reception to function. In contrast, EV-mediated signaling does not have a means of content screening, allowing for downstream signaling to occur as long as the cell can take up EVs and has the appropriate internal machinery necessary for signal transduction. Furthermore, EVs allow the delivery of multiple signaling molecules into the same cell, allowing for simultaneous activation of multiple pathways.