Detection of the G-CSFR in flow cytometry analyses. Expression of the G-CSFR on peripheral blood neutrophils from patients with SCN and a healthy control were determined using anti-G-CSFR antibody (MoAb 129; IgG1) and FITC-conjugated rabbit-antimouse IgG. The x-axis shows log scale fluorescence, the y-axis cell number. Two overlapping open histogramms of cells incubated with or without anti–G-CSFR antibody are shown. (A and B) Patients with severe congenital neutropenia, with point mutations in the cytoplasmic domain of the G-CSFR gene. (C) Healthy control (Table 1).