Fig. 1From: Anti-tumor effects of pigment epithelium-derived factor (PEDF): implication for cancer therapy. A mini-reviewModulation of the expression of PEDF affects tumor growth either (i) indirectly through the inhibition of angiogenesis, or directly via the prevention of cell proliferation, invasion and metastasis in concert with the promotion of cell apoptosis and/or differentiation. (−) PEDF means the absence of PEDF, (+) refers to the presence of PEDF, (→) means protein activation, and (—) means protein inhibitionBack to article page