The Zonula Occludens (ZO) proteins 1,2 and 3, also known as tight junction proteins, are peripheral proteins localizing at junctional sites(1). ZO proteins are known to be scaffolding proteins recruiting various types of proteins to the cytoplasmic surface of the junction, thereby contributing to the so called “junctional plaque”. ZO proteins also associate with gap junctions by directly interacting with connexins which points towards a general role of ZO proteins in intercellular adhesion and communication as determined using anti-ZO1 antibodies (2).