Heat map and volcano plot of genes in permanent versus deciduous pulp cells. A) Heat map of gene expression level in permanent pulp cells versus deciduous pulp cells. Each panel illustrates one comparison between permanent pulp cells and deciduous pulp cells from different subjects (n = 8). Red color indicates a high gene expression level, while green color means a low expression level in permanent compared to deciduous pulp cells. The data are z-score transformed. B) Volcano plot of up- and down-regulated genes in permanent versus deciduous pulp cells. Listed up- or down-regulated gene names have a significance of P ≤ .05.