As is all known, cells interact with each other throughout their lifetime and can attach to a surface, substrate or another cell. This process is called cell adhesion which was mediated by specialized protein complexes. The interactions between cells can be transient or long-lived based on the cellular structures and composition of the adhesion complex. Cellular adhesion is essential in maintaining multicellular structure and it can link cells in different ways such as adhesion junctions, tight junctions, desmosomes and focal adhesion.