Upon infection the median IL-8 expression by untreated macrophages and macrophages treated with IFN-γ was increased by 14-fold and 18-fold above baseline levels, respectively, while that by macrophages treated with GM-CSF in the absence and presence of IFN-γ only increased by 3 to 4-fold above baseline levels (Fig. 5B). The gene discussed is CXCL8; the disease is infection.