A method of inhibiting tumor cell chemotactic and/or chemoinvasion motility comprising contacting the tumor cell with an inhibitory amount of an agent selected from the group consisting of sphingosine-1-phosphate, derivatives of sphingosine-1-phosphate and mimetics of the sphingosine-1-phosphate or of the derivatives. A method of inhibiting phagokinetic activity of tumor cells and neutrophils comprising contacting the cells with a phagokinetic inhibitory amount of an agent selected from the group consisting of sphingosine-1-phosphate, derivatives of sphingosine-1-phosphate, and mimetics of the sphingosine-1-phosphate or of the derivatives. A method of inhibiting tumor cell metastasis comprising administering to a host in need of treatment a metastasis inhibitory amount of an agent selected from the group consisting of sphingosine-1-phosphate, derivatives of sphingosine-1-phosphate, and mimetics of the sphingosine-1-phosphate or of the derivatives, and pharmaceutically acceptable salts of the agent. A method of inhibiting inflammation due to motility and invasion into blood vessel walls of neutrophils comprising administering to a host in need of treatment an inflammation inhibitory amount of an agent selected from the group consisting of sphingosine-1-phosphate, derivatives of sphingosine-1-phosphate, and mimetics of the sphingosine-1-phosphate or of the derivatives, and pharmaceutically acceptable salts of the agent. A method of preparing sphingosine-1-phosphate and its derivatives.