Also, previous results by this group showed the inhibition of mRNAs for MMP-2, specularly to the increase of the mRNA for TIMP-2, to be associated to enhanced deposition of extracellular matrix within the tumour, increased thickness of the capsule surrounding it and appearance of a more defined wall around tumour blood vessels (Sava et al, 1996); all these events were matched to a marked reduction of the formation of spontaneous metastases. The gene discussed is MMP2; the disease is neoplasm.