IL2 and neoplasm: We also analyzed clinical survival outcomes, clinical response rates, immunophenotypes and tumor markers, and we hypothesized that the CIK cells fight with tumor cells in several different ways, including direct cellular interactions (Fas/FasL pathway, granzyme B), the secretion of cytokines (IFN-γ, TNF-α, IL-2) and antibodies, and immune response regulations (T-lymphocyte variations) [29].