Paxillin is a protein associated with focal adhesions, the close points of contact between a cell and the extracellular matrix. In addition to being involved in the regulation of cell spreading and motility, studies indicate that paxillin acts as an adaptor protein that conscripts various cytoskeletal and signaling proteins into a complex. This activity is thought to facilitate the coordination of downstream signal transmission. Focal adhesions were targeted in the fox lung cells featured in this section with mApple fused to paxillin. Cytoskeletal actin was labeled with a chimera of mEmerald and Lifeact.