Nectin is a cell-adhesion molecule that belongs to the immunoglobilin superfamily and is also known as the poliovirus receptor-related protein or PPR. Nectin family consists of Nectin 1 which expressed abundantly in the brain and Nectin 2 and 3 which are ubiquitously expressed in cells where cadherin are not expressed. Nectin-3 or PPR3 is a transmembrane protein that has three splicing variants: Nectin3α, Nectin 3β and Nectin 3g. Nectin-3 is mainly expressed in the testis and placental tissues and interacts in vivo with both long and short isoforms of afadin.