CAR T cells couple an extracellular antibody-derived receptor designed to specifically interact with a tumor antigen with a CD3-based intracellular activating domain.105 Second generation CAR T cells rely on molecular components of co-stimulatory molecules, such as CD28, ICOS, OX40 and 4-1BB, to enable sustained responses in the face of repeated antigenic stimulation.106. The gene discussed is CD28; the disease is neoplasm.