Gelatinase B/MMP-9 has been implicated in intravasation and subsequent metastasis formation [362] (Figure 6), with a particular role for inflammatory neutrophil-derived gelatinase B/MMP-9 highlighted in the promotion of haematogenous tumour cell dispersion of HT1080 fibrosarcoma and PC3 prostate carcinoma cells in xenograft models [12]. Here, MMP9 is linked to prostate carcinoma.