MMP9 and colorectal carcinoma: IHC analysis of tumors from vehicle-treated mice in the HCT116 model (Fig 6A and 6B) demonstrated that MMP9 expression in the xenograft tumor was generally analogous to that of human CRC (Fig 6D and 6E): In both cases, MMP9 was localized extracellularly in regions of desmoplasia and was produced by a subset of tumor cells, by non-inflammatory stromal cells such as fibroblasts and endothelial cells, and by inflammatory stromal cells such as macrophages and/or neutrophils.