Correlations between serum levels of sTREM-1 and CRP and expression of TREM-1 on monocytes and neutrophils in relation to the identified causative pathogen of CAP are shown in Figure 3 . Serum levels of sTREM-1 were greater among patients with CAP caused by Gram (+) cocci and Haemophilus influenzae than among patients with CAP caused by other pathogens.