MMP9 and neoplasm: Thus, ARF deficiency might modify the immune tumor microenvironment as a result of the induction of multiple activities including (a) immune suppression, through the production of the anti-inflammatory cytokine IL-10 and the secretion of Ccl22 and Ccl2 that attracts Tregs, (b) stimulation of angiogenesis through expression of VEGF and MMP-9, and (c) induction of matrix remodeling through the production of MMP-9, Fizz-1, and Ym1.