CD2-associated protein (CD2AP) is an adapter molecule of the immunoglobulin superfamily that was first identified as an SH3-containing protein that binds to the cytoplasmic domain of CD2. In the glomerulus, CD2AP is located in the cytoplasm beneath the slit-diaphragm, where it binds to the cytoplasmic domain of nephrin. CD2AP acts as a linker protein and may be involved in connecting nephrin to the actin cytoskeleton in podocytes, although direct evidence of this is still lacking. Interaction with CD2AP might be important in the steady-state situation. In addition CD2AP can facilitate nephrin-induced PI3K-AKT signaling, a pathway that has been shown to be important for nephrin-mediated actin reorganization in podocytes and protection of podocytes from apoptosis.