In human lung and gastric carcinomas, the MMP-2 activation ratio is enhanced; in canine tumor studies, higher MMP-2 and MMP-9 levels were observed in tumors than in inflammation, in malignant tumors than in benign tumors, in sarcomas than in carcinomas and in the advancing edge of canine malignances than in the center of canine tumors [11]. This evidence concerns the gene MMP9 and cancer.