MIP-1α induction and NK cell accumulation after treatments with rIFN-α. Liver homogenates or liver leukocytes were prepared from C57BL/6 (a and b), 129 (c and d), or C57BL/6 MIP-1α⁺ and C57BL/6 MIP-1α^– (e) mice treated with vehicle (black bars) or with rIFN-α (gray bars) as described in Methods. MIP-1α protein was measured in liver homogenates by ELISA (a and c). The levels of detection were 0.014 ng/g liver. Data represent the means ± SE (n = 4–8 mice tested individually). Liver leukocytes were analyzed by flow cytometry as described in Methods. Numbers (b, d, and e) of NK1.1⁺TCR-β^– and DX5⁺TCR-β^– NK cells per g liver are shown. Data represent the means ± SE (n = 4–8). Differences between vehicle control and rIFN-α treatments are significant at *P < 0.03, **P ≤ 0.01, and ***P ≤ 0.001.