Gene list stability. Sample size can determine the stability of rank gene lists in most cases. The y axis is the percentage of overlapping genes (POG) in the top 5% list between two compared studies and the x axis displays the logarithmic sample size. (a) The black stars indicating IR values ≤ 0.25 and correlating with Type 1 phenotypic classifications, show linear and thus stable behavior whereas the red stars indicating IR values > 0.25 and correlating with Types 2 and 3 phenotypic classifications, show less uniform distribution and are thus unstable (overall r2 = 0.15). (b) Gene list stability and the logarithm of the IR show a linear relation (with r2 = 0.76).