CD8A and neoplasm: (2) To study the trans-endothelial activity of antigen-specific CD8+T cells in the tumor microenvironment, this protocol utilizes purified naїve OT-I CD8+T cells from OT-I mice, which are C57BL/6J background and transgenic for the T cell receptor (TCR) recognizing the ovalbumin (OVA) peptide with amino acid residues 257–264 (SIINFEKL) presented by the MHC class I molecule H-2Kb.