Abstract: Compositions and methods are disclosed which employ PARIS proteins that are useful for suppressing proliferation of smooth muscle cells. Preferred PARISs are soluble proteins that are secreted by vascular smooth muscle cells, and include PARIS-1 (neuronal pentraxin 1), PARIS-2 (SBP (MIC-1, GDF-15), PARIS-3 (BTG2) and PARIS-4 (soluble fractalkine). Methods of preventing or treating restenosis by administering the new compositions are disclosed. Also disclosed are methods for treating patients undergoing angioplasty procedures, patients with atherosclerosis, and patients with other proliferative disorders, in order to suppress the growth of vascular smooth muscle cells or other cells that play a role in the particular proliferative disorder or condition. A method of screening mRNAs and identifying genes encoding PARISs is also disclosed.