CD8A and neoplasm: The increase in CD137 + CD8 + T and Ki-67 + CD8 + T-cell frequencies and IL-2 and CXCL10 levels in peripheral blood and the enhancement of CD8 + T-cell function and increase in CD8 + T-cell density at tumor sites after neoadjuvant therapy may indicate an obvious activation of local and systemic tumor immunity, which may be the mechanisms by which patients with pCR could clear tumor cells.