proMMP-9 inhibitor-3c (compound 3c) is a potent proMMP-9 inhibitor. proMMP-9 inhibitor-3c is specific for binding to the proMMP-9 hemopexin-like domain ( K d =320 nM). proMMP-9 inhibitor-3c disruption of MMP-9 homodimerization prevents association of proMMP-9 with both α4β1 integrin and CD44 and results in the dissociation of EGFR. This disruption results in decreased phosphorylation of Src and its downstream target proteins focal adhesion kinase ( FAK ) and paxillin (PAX).