SAM plot. SAM plot depicting the observed d-statistic versus the null distribution (built by permutation) and the two lines parallel to the diagonal quantifying the deviation (effect). Ideally, points with an effect large enough, be it positive (passing the upper line on the right) or negative (passing the lower line on the left) qualify as being differential. Transcriptional SAM plots present a typical S-shape (see Additional file 7), rather than the current flat trend.
Lu et al. BMC Medical Genomics 2014 7:12 doi:10.1186/1755-8794-7-12