MAGEA4 and melanoma: For instance, Iwamura et al. (45) showed that antigen-stimulated T cells expressed programmed death-ligand (PD-L) 1 and 2 and that electroporation of siRNA to downregulate expression of PD-L1/2 combined with retroviral transduction of a melanoma-specific TCR resulted in increased effector function against MAGE-A4+ cells.