K-mean clustering of the genes modulated upon exposure to Gelsemium s. dilutions. The expression profile of 56 genes significantly modulated by Gelsemium s. 2c was evaluated also upon exposure to increasing Gelsemium s. (G) dilutions. Fold change was calculated as the difference between Log2 fluorescence values of each Gelsemium s. dilution and the mean Log2 fluorescence of the controls. Data are means of 4 replicate experiments. A. K-mean clusters (KMC) visualized as a colour-coded heat map. The down-regulated genes (green) with similar expression profiles were grouped in 4 clusters and the up-regulated genes (red) in one cluster. B. Centroid graphs of the mean fold change of genes in the 5 clusters obtained in KMC analysis.