For this purpose, cryopreserved PBMC were thawed and stimulated with a panel of cognate tumor- or viral antigens and their ability to produce key cytokines (i.e. IFN-γ, IL-2 and/or TNF-α) and to express the cytolytic marker perforin were assessed using polychromatic flow cytometry. The gene discussed is PRF1; the disease is neoplasm.