MMP2 and melanoma: Villares et al. [75] used systemic delivery of PAR-1 small interfering RNA (siRNA) incorporated into neutral liposomes to inhibit melanoma growth in vivo and found a concomitant decrease in VEGF, IL-8, matrix metalloproteinase-2 (MMP-2) expression levels, as well as decrease in blood vessels density in tumor samples from PAR-1 siRNA treated mice compared to control animals.