MMP1 and gastric carcinoma: Possible explanations for this observation may reside in the degree of tumor invasion, further, metastasis in gastric carcinoma might also determined by the response to growth factors and cytokines besides the presence of 2G, G, T, C, C alleles (respectively for MMP-1.1, -1.2, -1.3, -1.4 and -1.5) in the MMP-1 promoter.