IL2 and neoplasm: Impact of PF Combined with Sor on Anti-Tumor Immunity in Model Mice. To determine if the anticancer effect of PF combined with Sor resulted from enhanced immunological responses, the infiltration of T-cell subsets in tumor tissue, levels of IFN-γ and IL-2 in peripheral blood, and CTL activity of normal mice's Splenic lymphocyte against model mice's tumor cells were examined.