MMP9 and neoplasm: While no significative differences were observed in the levels of MMP-9 between control and açaí treated groups (Fig. 4c and f), the immunostaining of VEGF and its receptor VEGFR-2 reveals a substantial increase in the expression of these two proteins in the tumor stroma, as well as in the glandular compartment from control group samples (Fig. 4a and b).