Figure 4

Cumulative frequency distribution of 1-p (p-value plot) for expressed genes and 'not expressed' genes. The distribution for expressed genes is green and the distribution for 'not expressed' genes is black. The p-values are from the t-tests of a gender difference. The dashed lines indicate a theoretical uniform distribution for p-values under the null hypothesis; the black line assumes that all of the 'not expressed' genes fit the null hypothesis and the green line assumes that 92% of expressed genes fit the null hypothesis.