NCAM1 and neoplasm: Cytokine-induced killer cells (CIKs), are heterogenous ex vivo expanded T lymphocytes [55], characterized by the presence of two main subsets: the first, with a CD3 + CD56+ phenotype, mainly responsible for the anti-tumor activity of CIKs and the second (CD3 + CD56-) more similar to conventional T lymphocytes [56].