To this end, the expanded PD1+ CD8+ T cells were stimulated by anti-CD3/anti-CD28 and subsequently assayed for the expression of CD107a (a marker of degranulation), IFN-γ, granzyme B and IL-2 by flow cytometry; the corresponding parental PD1+ CD8+ T cells from cancer patient PBMC were included as the control. The gene discussed is CD28; the disease is cancer.