Then, the DOC concentration in tumor tissue at different time (5 min, 30 min and 60 min) after tail intravenous injection with FA-CD-PLLD/DOC/MMP-9 were calculated, average concentrations of DOC in both HNE-1 and CNE-2 tumor was 2.33 and 1.16 μg/g at 15 min, 5.39 and 2.65 μg/g at 30 min, 6.97 and 3.30 μg/g at 60 min respectively, and the results were shown in Figure 4B. The gene discussed is MMP9; the disease is neoplasm.