These antibodies have one arm that binds to a specific antigen on cancer cell surfaces, like CD19 or HER2, and another arm that binds to CD3, a component of the T cell receptor complex on T cells.467,468 Bispecific antibodies physically connect T cells to tumor cells, positioning immune cells closer to cancer cells and enhancing T cell activation and subsequent tumor cell lysis. The gene discussed is CD19; the disease is cancer.