T-score distributions in real and permuted data sets.

(A) The distributions of the T-scores in the real (blue) and permuted (red) data sets. The variance of the distributions is larger for the T-scores on the real data, even though the means are similar. Since in the IBD and SLE data sets most T-scores are close to zero, we also show the upper tails of their distributions. (B) The standard deviation of the T-scores in the real and permuted data sets. The standard deviation is larger in all real data sets, indicating that high T-scores (in absolute value) are more probable in the real data sets. Permuted data sets were generated by shuffling sample labels. Results are the average of 50 permutations.