(A) Schematic of ombrabulin signaling to NWs. Ombrabulin upregulates the presentation of p32 in tumors, which is then targeted by NW-LyP1. (B) Experimental timeline for testing the signaling system. (C) Quantification of NW homing to tumors as a function of ombrabulin dosage (** P < 0.01, Student’s t-test; n = 3–4 mice, s.e.). (D) Representative near-infrared fluorescent scans of NW homing to tumors in response to increasing doses of ombrabulin. Tumors were excised and imaged at 24 hrs post-NW injection. (E) Immunofluorescent staining of NWs in tumors without (0 mg/kg) and with (60 mg/kg) ombrabulin (green = NW, red = p32 staining, blue = nuclear stain; scale bar = 100 µm).