CD8A and neoplasm: CD8+ T cells from OT-I mice specifically recognize the OVA peptide of amino acids 257–264 (SIINFEKL)34.To assess their tumor-killing capacity, CD8+ T cells and non-CD8+ T cells from the spleens of OT-1 mice were then co-cultured with MC38 cells overexpressing OVA257–264 (Fig. 3g and Supplementary Fig. 1p).