Figure 1
Example of the identification of the O i in the meta-analysis method. Each of the circles represents a hypothetical dataset (S 1 to S 4 ). The numerals are the number of genes differentially expressed in the datasets represented by that area of overlap of the circles. The value O i is defined as the number of genes differentially expressed in exactly i number of datasets. In the example, O 1 is 85 since that is the number of genes differentially expressed in 1 study, whereas O 4 is 1 since only one gene is present in the area overlapping all 4 studies.