The effect of in vivo rhIFN-γ administration on monocyte surface molecule expression. In vivo rhIFN-γ was associated with a significant increase in expression of FcγRI (A), FcγRII (B), FcγRIII (C), HLA-DR (D), CD11a (F ), CD11b (G), and CD18 (H). Monocyte expression of CD14 (E) failed to change significantly. Results are reported as FITC MESF ± SE from patients (•; n = 12) who received rhIFN-γ per protocol and untreated normal controls (○; n = 6). Asterisks indicate statistical significance (P < .05).