Several MMPs, in particular the gelatinases MMP-2 (Jones et al, 1999; Duffy et al, 2000; Talvensaari-Mattila et al, 2001, 2003; Baker et al, 2002; Grieu et al, 2004; Li et al, 2004; Sivula et al, 2005) and MMP-9 (Chantrain et al, 2004; Li et al, 2004; Pellikainen et al, 2004), have been recently studied as prognostic factors in breast cancer, being associated with a poor outcome in various subsets of patients. The gene discussed is MMP9; the disease is breast carcinoma.