Cell adhesion molecules (CAMs) are cell surface glycoproteins mediating cell-cell and cell-matrix interactions which play a vital role in the embryonic development of the nervous system as well as in the maintenance and nerve regeneration in adults. In the central nervous system (CNS) three main CAMs, such as neural cell adhesion molecule (NCAM), L1 and N-cadherin have been characterized. In addition to their adhesive properties, CAMs are involved in cell migration, growth of axons, nerve pathways formation and synaptogenesis. The binding of CAMs can activate transmembrane-signalling reactions and thereby contribute to the initiation of cellular response in regulation of synaptic plasticity. CAMs play an important role in learning and memory. The role of CAMs in abnormal development and malignancies provide a wide field of research for diagnostic and therapeutic applications. (Ref. 36.)