Effects of BMP 2, 4 and 7 and gremlin and noggin on CCL-171 cells. A) A multiclass SAM analysis was performed to select for genes that are differentially expressed in response to BMP2, BMP4, BMP7, Noggin or Gremlin using a FDR of less than 1% as the cut-off value. The selected genes were organized by unsupervised hierarchical clustering and gene expression changes plotted in a heatmap. The legend bar maps color versus the magnitude of changes in transcript levels relative to the mock-treatment level. The “common BMP induced gene list” is indicated, and the genes included in the list are shown in Additional file 5: Table S5. B) Scatter plots demonstrating the correlation of expression changes of all genes identified by SAM upon stimulation with BMP2 (x-axis) versus BMP4, BMP7, Noggin and Gremlin( y-axis). The Pearson correlation coefficient r is given. ***corresponds to a p-value < 0.001.