CD64 Index levels were higher (mean ± SEM) in ICU infection patients then ICU control and normal control patients (2.62 ± 0.39 vs. 1.31 ± 0.24 vs. 0.46 ± 0.04, p < 0.01 for ICUi vs. ICUc, p < 0.001 for ICUi vs. C). The gene discussed is FCGR1A; the disease is infection.