Two-way hierarachical clustering on NB vs. ND and T vs. NB. The differentially expressed genes with fold change > 4 in the NB vs. ND and T vs. NB comparisons were applied in this analysis. Each row represents a gene and each column corresponds to a sample. Expression of each gene was median-centered across all specimens for that gene. Shades of red represent degrees of increasing expression, and shades of green represent degrees of decreasing expression.