MMP9 and breast cancer: Since MMP-2 and MMP-9 (gelatinase A and B) have been shown to be associated with breast cancer, expression of HER2/neu, and an unfavorable prognosis [15,16] and because TIMP-2 also seems to have cell growth promoting and anti-apoptotic activity [30], serum MMP-2, MMP-9 and TIMP-2 were also included in the present analysis.