 Structural studies have shown that these domains share a common core Greek-key beta-sandwich structure, with the types differing in the number of strands in the beta-sheets as well as in their sequence patterns.Immunoglobulin-like domains that are related in both sequence and structure can be found in several diverse protein
families.Ig-like domains are involved in a variety of functions, including cell–cell recognition, cell-surface receptors, muscle structure and the immune system.