CCR7 and neoplasm: Furthermore, the relative frequency of suppressive cell types such as myeloid-derived suppressor cells (MDSC) and tumor-associated macrophages (TAM) increase while NK cell frequency decreases over time with NBL growth (47), and the phenotype of tumor-infiltrating CD8+ T cells is different from matched samples of peripheral blood CD8+ T cells in patients, with the tumor-infiltrating cells acquiring an effector memory phenotype, identified by the cell surface markers CD25, CCR7, and CD45RA (48).