PBMCs from SCID and non-SCID piglets incubated in the presence or absence of recombinant human IL-2 (rh IL-2) and tested for cytotoxicity against A375-SM, K562, or PANC-1 human cell lines. Percent Cytotoxicity was reported for 5:1, 10:1, and 20:1 effector:target ratios. SCID PBMCs had the highest percent cytotoxicity (dotted line) compared to non-SCID (NS) littermate cells (solid line). PBMCs not treated (activated) with IL-2, but rather treated with media alone, did not lyse target cells from any of the tumor lines (gray lines).