Since filter cut off studies implicate proteins in the 50–100 kDa range to possess the tumor invasive activity, we anticipate that some of this activity resides in MMPs, more specifically MMP-2 (72 and 62 kDa), -9 (92 and 82 kDa) and -3 (54 kDa) because the MW of these MMPs fall in the range of 50–100 kDa. This evidence concerns the gene MMP2 and neoplasm.