Sphingosine-1-phosphate inhibits PDGF-induced chemotaxis of human arterial smooth muscle cells: spatial and temporal modulation of PDGF chemotactic signal transduction - Bornfeldt, KE; Graves, LM; Raines, EW; Igarashi, Y; Wayman, G; Yamamura, S; Yatomi, Y; Sidhu, JS; Krebs, EG; Hakomori, S; Ross, R (J Cell Biol, 1995)