Expression of cytolytic factors in CD8⁺ T cells from patients with B-NHL. T lymphocytes from a lymph node biopsy of a patient with FL were characterized for expression of CCR7 and perforin or granzyme B before (A) and after (B) culture for 2 weeks with 50 ng/mL IL-2. Numbers in the dot plots indicate the fraction of positive cells in each quadrant. (C) Expression of cytolytic factors perforin (○) and granzyme B (□) in T cells isolated from peripheral blood of patients with CLL, or from lymph node biopsies (•, ▪) of patients with FL. Expression of perforin and granzyme B was also reevaluated after culture with IL-2.