T cells engineered with an affinity-enhanced HLA-A*02-restricted TCR isolated from immunized mice with CEA peptide led to severe transient colitis [118]; whereas an affinity-enhanced HLA-A*02-restricted MAGE-A3/A9/A12-specific TCR derived from MAGE-A3-vaccinated transgenic mice caused neurotoxicity due to the recognition of MAGE-A12 expressed by brain cells [125]. The gene discussed is MAGEA3; the disease is colitis.