LeY T cells have an effector memory phenotype and respond to Lewis antigen expressing cell lines by secreting IFN-gamma. Following the transduction culture, the CD8⁺ LeY-T cells (A) expressed high levels of perforin and an EM phenotype. In (B), LeY T or empty vector control T cells were co-cultured with tumour cells overnight and intracellular cytokine secretion assay performed. The LeY CD8⁺ T cells responded to Lewis antigen expressing OVCAR cells by secreting IFN-gamma, whereas no response was observed with the negative cell line HCT-116.