Hierarchical clustering of the selected genes for the Liver Toxicity study. Hierarchical clustering of the biological samples using the extracted genes from sPLS-reg network. Agglomerative hierarchical clustering was derived using the Euclidean distance as the similarity measure and Ward methodology. The resulting heatmap contains the genes in rows and samples in columns with red indicating up regulation, green down regulation and black no change. On the top of the heatmap, clusters of the biological samples are colored in violet, cyan and magenta for no, moderate or severe necrosis respectively. On the left hand side of the heatmap, gene clusters are shown (dark brown, brown, yellow and orange).