Venn diagram showing the number of transcripts identified present in each cell population. The circles represent a specific cell population with the numbers representing the genes present in each sample (P < 0.001). Numbers in the outer portion of each circle are specific to that sample. The number in the innermost portion of the diagram represents transcripts expressed in the three populations (1361). Likewise, the numbers in the portions of the diagram shared by two circles represent genes expressed in those samples but not in the exclusive sample.