Abstract
Microarrays are made by immobilizing to a solid support thousands of DNA probes that detect soluble complementary target sequences using the hybridization pairing rules of nucleic acids. Receptor triggering induces a cascade of signaling events that often involves the modulation of gene expression. In the last decade, the development of microarrays has provided scientists with an innovative tool to interrogate the cell transcriptional profile at a global level and to characterize genes according to their behavior in different conditions. This chapter outlines the use of microarrays as an innovative approach to study the global effect of transmembrane-receptor triggering. The effect of formyl peptides receptors activation on the gene transcriptional program of human monocytes is described as a model.