Correlation between gene expression profiles and laboratory indices of disease progression. (a) Clustered correlation analysis. Gene expression data were correlated with phenotypic measurements using clustered correlation analysis 33. The correlation coefficient values of each probe set to laboratory measurements were presented in a heat map visualization generated in Spotfire DecisionSite. The measurements are as follows: animal gross weight (weight), paw size (paw size), total white cell count (WBC), total lymphocyte count (LY), percentage lymphocyte of total WBCs (LY%), total monocyte count (MO), percentage monocyte count (MO%), total neutrophil count (NE), percentage neutrophil count (NE%), total eosinophil count (EO), percentage eosinophil count (EO%), total basophil count (BA), and percentage basophil count (BA%). (b) Correlation of Versican expression with neutrophil count. The expression level (signal intensity) of Versican from the Affymetrix microarray experiment were plotted, together the neutrophil count (K/μl) for each animal that was used in our microarray study. CIA, collagen-induced arthritis.