CCL2 and neoplasm: Encapsulation of oncolytic adenovirus (Ad[I/PPT-E1A]) into liposomes coupled to chemokine CC motif ligand 2 (CCL2), which upon intravenous delivery binds to circulating monocytes expressing chemokine CC motif receptor 2 (CCR2), takes advantage of the aggregation of monocytes to hypoxic tumor vessels to deliver encapsulated OVs targeting tumor sites [133].