A polysulfonated naphthylurea that inhibits the binding of calmodulin to recognition sites on the ryanodine receptor-1 (IC50 = 4.9 μM), blocks G protein coupling to GPCRs, and non-selectively antagonizes P2 purinergic receptors (10-100 μM); acts as a non-specific competitor of glycosaminoglycan binding to a variety of targets including TGFβ, PDGF, and FGF and additionally inhibits insulin-like growth factor-l, EGF, PKC activity, TNF, IL-2, transferrin, and Apo-B