Confocal microscopic analysis of the cross-linking of Jurkat and MDA-MB-468 cells induced by SMART-Exos. Fluorescently labeled target cancer cells (red) and Jurkat cells (green) were mixed at a 1:3 ratio and incubated for 5 h in the presence of αCD3/αEGFR SMART-Exos or a mixture (1:1) of αCD3 SMART-Exos and αEGFR SMART-Exos. Nonbound cells were washed away by PBS. Scale bars: 50 μm. (Adapted with permission from J. Am. Chem. Soc. 2018, 140, 48, 16,413–16,417. Copyright (2018) American Chemical Society)