In accordance with the literature, the percentage of circulating cytotoxic T cells was significantly higher (CD8+CD3+CD4−CD56−; healthy individuals, 27.11% ± 8.03%; breast cancer patients, 32.48% ± 9.65%) than the percentage of cytotoxic T cells in the lymph nodes (15.68% ± 8.12%) (Figure 1A). Here, CD8A is linked to breast cancer.