MMP1 and osteosarcoma: To identify the mediator of TSP‐2‐promoted osteosarcoma migration, we examined levels of MMP‐1, MMP‐2, MMP‐3, MMP‐7, MMP‐9, MMP‐12 and MMP‐13 mRNA expression following TSP‐2 stimulation (Figure 2A,B).