Expression of FcγRII/III after a 30-minute exposure to G-CSF. FcγRII/III cell surface expression was evaluated by flow cytometry using FITC-conjugated rat antimouse FcγRII/III mAb (solid lines). (A-B) Cells transfected with WT G-CSF-R; (C-D) cells transfected with mutant G-CSF-R; (A,C) no G-CSF stimulation; (B,D) stimulation with G-CSF (300 ng/mL) for 30 minutes. Dotted lines indicate fluorescence of isotype-matched antimouse Ig-FITC–incubated cells.