An illustration showing the mechanism of action of the immunotherapy drug teclistamab. The image shows a multiple myeloma cell with BCMA receptors on its surface, a T cell with CD3 receptors on its surface, and the drug teclistamab. Teclistamab is shown as a Y-shaped object. Half of the Y is labeled the BCMA arm, and the other half of the Y is labeled the CD3 arm. The drug's BCMA arm reaches toward the multiple myeloma cell's BCMA receptors. The drug's CD3 arm reaches toward the T cell's CD3 receptor. An arrow from the T cell to the multiple myeloma cell is labeled "cell killing."