The many biological responses documented for lysophospholipids that include
lysophosphatidic acid and sphingosine 1-phosphate can be mechanistically attributed to
signaling through specific G protein-coupled receptors. At least nine receptors have now
been identified, and the total number is likely to be larger. In this brief review, we note cogent
features of lysophospholipid receptors, including the current nomenclature, signaling
properties, development of agonists and antagonists, and physiological functions.