Fas activation induces cytoplamsic translocation of HMGB1 in primary murine peritoneal mϕ. Primary murine peritoneal mϕ were stimulated with recombinant mFasL (0 - 0.5 μg/ml) for 2 hr. Cytoplasmic and nuclear extracts were prepared as described in Materials and Methods, and HMGB1 content was determined by immunoblot. Equal loading of samples was confirmed by concomitant immunoblot analysis of the respective fractions using antibodies specific for a nuclear (PCNA) or cytoplasmic (β-actin) protein. Blots are representative of 3 independent experiments with similar results.