MMP3 and triple-negative breast carcinoma: Using an intratibial model of bone metastasis, we showed that the inflammatory cytokine IL-6 as well as matrix remodeling factors MMP3 and type I collagen were reduced in the endosteal and hematopoietic niches of the tibia with tumors composed of an admix of EOs plus triple-negative breast cancer cells, as compared to admixes of “uneducated” osteoblasts plus triple-negative breast cancer cells, or triple-negative breast cancer cells injected alone.