MMP9 and ovarian cancer: As supporting evidence, M2 macrophage (or tumor-associated macrophage, TAM)-secreted MMP9 promotes release of membrane-associated heparin-bound epidermal growth factor (HB-EGF) from the same cells, a process that increases expression of MMP9 in OVCA433 ovarian cancer cells, generating a positive feedback loop to drive growth factor release and accelerate proliferation via co-culture (Carroll et al., 2016).