Pigment epithelium-derived factor (PEDF) is a member of the superfamily of serine protease inhibitors and was initially isolated from fetal human retinal pigment epithelial cells.4, 5 PEDF is highly expressed in the adipose tissue, liver, eye, heart, skeletal muscle, spleen, brain and bone.6 PEDF exerts a range of biological effects in many physiological and pathophysiological processes, including neuroprotection, fibrogenesis and inflammation.7, 8 Previous studies have shown that PEDF has complex and often opposing roles in cancer angiogenesis, tumor growth and metastasis. The gene discussed is SERPINF1; the disease is cancer.