C J774A.1 macrophages were stimulated with zymosan after FK506 (10 ng/ml) or control treatment, and macrophage nuclear extracts were probed by Western blot for NFATc2 and NF-κB translocation. NFATc2 and NF-κB nuclear translocation was observed, which was maximal at 1 h p.i., in stimulated macrophages. FK506 specifically inhibited NFATc2 translocation, but had no effect on NF-κB. 