The present invention relates to method of treating a patient with a condition involving increased vascular permeability or increased angiogenesis comprising administering to the patient a therapeutically effective amount of PEDF, PEDF 44 AA peptide, a homolog of the PEDF 44 AA peptide, a homolog of the PEDF 44 AA peptide wherein amino acid residues glutamateat the (101) amino acid position, isoleucine at the (103) amino acid position, leucine at the (112) and serine at the (115) amino acid position are unchanged, or an agent that activates the PEDF receptor. Conditions for treatment include, but are not limited to, sepsis acute respiratory distress syndrome, nephrotic syndrome, diabetic neuropathy, preproliferative diabetic retinopathy, cancer or proliferative diabetic retinopathy.