Unsupervised bioinformatical analyses, including weighted gene cluster network analysis (45, 46) and the innovative method FlowSets (see Supplementary Materials and Methods), confirmed infection-specific up-regulation of distinct gene clusters implicated in leukocyte migration, autocrine signaling, and inflammatory responses, as prominently marked by enhanced expression of S100 genes (S100A6, S100A8, S100A9, S100A11, and S100A12) and granule contents (GCA; Fig. 2, F to J). The gene discussed is S100A9; the disease is infection.