In addition, the association of CD3 with the TCR–peptide–MHC complex transmits the activation signal to intracellular signalling molecules to initiate a signalling cascade in the T cell.

CD20 × CD3 bispecific antibodies bind to both CD20 on malignant B cells and CD3 on T cells, bringing them into close proximity, which triggers T cell-mediated killing of the targeted B cells.