Figure 1  Outline of two microarray integration methods: (a) meta-analysis (“late integration”). Individual case-cohort microarray studies are pre-processed and each study is used to identify ranked gene lists which are then combined in the final step; (b) Cross-platform merging and normalization (“early integration”). After pre-processing of individual studies, a single unified case-cohort dataset is generated (“clustered” into cases and cohorts, indicating removal of batch to batch variation) and in this example, used to identify a ranked gene list.