FIG. 2.

Two-way hierarchical cluster analysis of microarray data sets from SARS patients with or without fever. A total of 5,555 genes were identified by ANOVA (F-test, P < 0.05) based on the presence (red boxes in the “Fever” column) or absence (blue boxes in the “Fever” column) of a fever of ≥38°C from 60 data sets for 40 SARS patients throughout illness. SARS patient data sets were normalized gene by gene against the means for healthy controls (n = 10). Patient data sets were analyzed by two-way hierarchical clustering (red boxes indicate upregulation and blue boxes indicate downregulation of genes of the indicated functions) and labeled by the presence or absence of fever. The general status of a SARS patient (for the “Status” column, black boxes indicate the precrisis phase, white boxes indicate crisis and green boxes indicate patients at discharge) is also noted as defined in the text. The major GO terms according to DAVID for five clusters have been placed above the heat map, and two patient clusters are labeled as described in the text.