After targeting MMP-9 with the specific MMP-9 inhibitor JNJ0966 (Selleckchem, Houston, TX, USA), which blocks the conversion of pro-MMP-9 to active MMP-9, we observed a significant decrease in tumor size after 7 days of incubation on the CAM compared with day 1 (d1: 12.15 μm2 vs. d7: 2.8 μm2 mean value, with a mean d1–d7 difference of 9.35 μm2). The gene discussed is MMP9; the disease is neoplasm.