PTK2 and schizophrenia: Reelin may also activate focal adhesion kinase (FAK) pathway via interaction with integrin receptors α3β1 (ref. 14) and α5β1.15 Focal adhesions are cell membrane structures that link the extracellular matrix (ECM) with the intracellular actin cytoskeleton and are essential for cell adhesion and motility.16 The FAK signaling pathway, which regulates cell adhesion to extracellular proteins via integrin receptors, is impaired in schizophrenia patient-derived olfactory cells.17 The exact mechanism of reelin-dependent modulation of cell migration remains debatable.