ESNF20 and ESNF31 are the most recent examples of a classof NIR fluorophores with the structure-inherent targetingproperty.18–20 That is, there is something, as yet unidentified,in their chemical structure that favors uptake in the AG, whilestill retaining the NIR fluorescence property. Such bifunctionalmolecules provide the most compact possible chemical structurefor image-guided surgery because conjugation to a separatetargeting ligand is not needed.