The monoclonal antibody 6A6 recognizes mouse CD96. CD96 or T cell-Activated Increased Late Expression (TACTILE) is an ~67 kD immunoglobulin-like protein expressed on natural killer (NK) and T cells. CD96 belongs to the Ig-super family, consisting of three Ig-like domains and an extended serine/threonine/praline-rich stalk in the ectodomain. CD96 is upregulated upon T cell activation and is involved in engagement of diseased cells and cell movement towards areas of inflammation. Mouse CD96 binds to CD155 and nectin-1. CD96/CD155-interaction is preserved between man and mouse although both receptors are only moderately conserved in amino acid sequence. The monoclonal antibody 6A6 completely inhibits binding of CD96 to both recombinant mouse CD155 and mouse nectin-1. Also, T cell adhesion to insect cells expressing mCD155 is blocked by this monoclonal antibody, however, depending on the T cell subtype.The monoclonal antibody 6A6 was raised after immunization of rats with purified recombinant mCD96-hIgG1.