Effect of gene list selection criteria on the degree of inter-platforms concordance. Number of overlapping genes (y-axis) in the 2 and 3 lists of DEG according to the size of the list (x-axis). For each platform, the list was constituted by selecting DEG (Pc < 0.05), then within this list genes were ranked according to decreasing fold change. The number of overlapping genes between lists was calculated for increasing list size. When the number of probes in the lists was approximately 3800, the number of overlapping genes reached a plateau. The "best 3800" set of probes was defined accordingly.