PGE2-induced angiogenesis in vitro requires the presence of MT1-MMP. MLECs from WT (MT1-MMP+/+) or MT1-MMP KO (MT1-MMP−/−) mice were seeded onto Matrigel in the presence or absence (NS) of PGE2 (1 μM) or the proangiogenic factor CXCL12 (10 nM). Cord formation was quantified after 6 hours. Data are presented as the fold induction above cord formation by untreated cells, and are the means plus or minus SD of 3 to 5 independent experiments. The absolute value corresponding to FI = 1 was 66 cords/field. All experiments were run in triplicate. *P < .05 vs KO control; **P < .01 vs WT control; #P < .001 vs WT control.