Unsupervised clustering of LPS-stimulated CD14+ MP exposed to distinct cytokine treatments. CD14+ MP were stimulated in parallel with LPS and exposed after 1 hour to 42 individual cytokines. Antisense RNA obtained 9 hours following LPS stimulation, was hybridized to custom made 17 k cDNA arrays. Unsupervised Eisen  clustering was applied to the complete, unfiltered data set of 98 experiments. A375 is a melanoma cell line that was used for quality control alternating conventional (Cy5, red) or reciprocal (Cy3, green) labeling every 25 experiments as previously described . A total of 2063 genes were analyzed. These genes were obtained by filtering the 16,000 genes and analyzing only those present in greater than 80% of samples and with at least one observation greater than 2 logs. The expression of each gene was average corrected among the cytokines.