CASK, also named as LIN2, belongs to the MAGUK family. It is a multidomain scaffolding protein with a role in synaptic transmembrane protein anchoring and ion channel trafficking. It contributes to neural development and regulation of gene expression via interaction with the transcription factor TRB1. CASK binds to cell-surface proteins, including amyloid precursor protein, neurexins and syndecans. It may mediate a link between the extracellular matrix and the actin cytoskeleton via its interaction with syndecan and with the actin/spectrin-binding protein 4.1. Defects in CASK are the cause of mental retardation X-linked CASK-related (MRXCASK) . Defects in CASK are the cause of FG syndrome type 4 (FGS4). This antibody can recognize all the isoform of CASK.