Most importantly, however, incubation of tumor cells with gp100-reactive T cells in the presence of antibodies that block the interactions with lysosomes/secreted granules (i.e. LAMP1, CD95, or CD63) did not alter T cells capacity to induce a cell-in-cell formation, suggesting that these molecules are also expressed on T cell membranes (Figure 4F). This evidence concerns the gene CD63 and neoplasm.