MMP9 and cancer: The number of TRAP+ osteoclasts induced by the conditioned medium from HOXC10-inhibited cancer cells were dramatically reduced and the reduced reversed by NOD1 overexpression (Fig. 5h) Furthermore, qPCR results showed a marked decrease in MMP9 transcription was observed from HOXC10 knockdown cancer cells conditioned medium induced osteoclasts (Fig. 5i), which were partially abrogated by NOD1 overexpression (Fig. 5i), indicating a NOD1-dependent effect.