Expression of granzyme B in IL-2–stimulated cord blood and BM cells. Cord blood (n = 3) and BM (n = 4) mononuclear cells were cultured in IL-2 (500 U/mL) for 3 days. Samples were extracted, electrophoresed on 15% nonreducing SDS-PAGE gel, and immunoblotted using anti-granzyme B monoclonal antibody. AEC was used to visualize immunostaining.