Expression of FcγRI and FcγRII PMNs after exposure to rhG-CSF. Flow cytometric histograms of freshly isolated PMNs from a normal donor (—), PMNs from the same normal donor after treatment with 10 ng/mL rhG-CSF for 24 hours in vitro (···), or PMNs from a patient treated with rhG-CSF in vivo (bold line). Isotype control staining is depicted by the solid histogram. Results are representative examples of four independent experiments.