Comparison of gene expression patterns of sickle cell disease to those of a general inflammatory state. Genes were selected based on the comparison of mean gene expression levels between sickle cell disease patients and African-American healthy volunteers using a 1.2 fold-change cut off, an average difference more than 20 filter in either sickle cell disease or control group and a less than or equal to 5% false discovery rate multiple comparisons correction. Cluster analysis was applied to gene expression data from sickle cell disease patients of HbSS phenotype on (SS*) or off (SS) hydroxyurea therapy, African-American healthy volunteers (AA), a separate set of healthy volunteers (Pre LPS), and these same volunteers following intravenous endotoxin infusion (Post LPS). This figure shows that there are similarities in gene expression patterns for these 112 genes between sickle cell disease and an inflammatory state induced by endotoxin infusion. Importantly, there are clusters of genes, marked by the blue bars to the left of the figure, that show differential expression between sickle cell disease and endotoxin infusion, suggesting that the gene expression changes observed in sickle cell disease are not due solely to a generalized inflammatory state but are specific for sickle cell disease.