Outside-in signaling through α_IIbβ₃ in platelets, emphasizing the sequential nature of the process. First, agonists induce affinity modulation and ligand binding promotes integrin clustering (1). Second, the ligated and clustered integrins trigger early outside-in signaling events, such as activation of Syk and Src (2). Although not shown, this may be associated with filopodial extension. Finally, activation and/or cytoskeletal translocation of FAK, protein tyrosine phosphatases (PTP), and many other important enzymes (Etc.) occurs, coincident with their assembly into mature focal adhesions that are connected to actin stress fibers (3).