Focal Adhesion (FA) plays a central role in cell attachment and migration; it controls embryogenesis, tissue repair, inflammatory response and tumor invasion. Cell migrates through the regulated alternative assembly and disassembly of Focal Adhesion. It pulls the cell body forward by grabbing and releasing Extra-Cellular Matrix (ECM). For its importance, the mechanism of FA controlling has been a major research focus during the past 10 years. However, the fundamental question of how the FA assembly and disassembly are precisely controlled remains unanswered. PAK, FAK, Paxillin and GIT1 are important structural and signaling components in FA. To answer the critical question in the field of cell adhesion and migration, Nuclear Magnetic Resonance (NMR) Spectroscopy is used to study the structures and regulations between these proteins. This book focuses on the structural and functional study of GIT1 and discusses the Focal Adhesion control through some novel discoveries. For the first time, this work has consolidated existing evidences, including some controversial findings, to provide an exciting working model on the FA regulation.