Figure 2. Shared gene clusters between beta cells, neuronal cells and immune cells.

The 503 human probe sets corresponding to the 332 conserved beta cell marker genes are visualized by hierarchical clustering in the Human Genome Atlas data set [3]. At least 15% of beta cell marker genes show near absolute beta cell selectivity (beta cell selective cluster B). Beta cells also share an equally extensive cluster (15%) with various brain regions (neuroendocrine cluster A), and an even larger cluster (30%) with immune and gut mucosal cells (gut/immunological cluster C). Statistical enrichment analysis indicates that these clusters accentuate different functions proper to the specialized beta cell phenotype. Blue to red correspond low to high relative expression, as shown in legend (bottom). Relevant genes of clusters A, B and C are shown in Fig. 3.