NCAM1 and neoplasm: reported the ability of exosomes from the human CCA cell line RBE to block the anti-tumor actions of cytokine-induced killer (CIK) cells through reducing the numbers of CD3(+), CD8(+), NK (CD56[+]), and CD3(+)CD56(+) cells, as well as the production of tumor necrosis factor-α (TNF-α) and perforin (88).