Figure 3

The top 10 pathways of the clusters based on the within-twin pair differences in gene expression. Differentially expressed genes for each cluster (FDR<0.05, n=274 for Cluster 1, n=728 for Cluster 2, n=828 for Cluster 3) were entered into IPA to produce the pathways. (a) Cluster 1, (b) Cluster 2 and (c) Cluster 3. The y axis displays the −log of P-value which is calculated by Fisher's exact right-tailed test. A-log(P-value) of 1.3 is indicative of P-value of 0.05. The percentage of upregulated (dark grey) and downregulated (light grey) genes in the heavy co-twins in the data set is represented. The white blocks represent the genes that belong to the pathway according to IPA analysis but did not reach significance. For some pathways, IPA was able to conclusively provide activation scores: (z-scores which show statistical significance of the observed number of ‘activated’ and ‘inhibited’ genes; <0: inhibited, >0: activated). z-scores >2 or <−2 are considered significant. For Cluster 2, IPA predicted the following pathways to be downregulated (EIF2 signalling (z=−2.309) and the following pathways to be upregulated: mTOR signalling (z=0.378) and IL-8 signalling (z=1.414). For Cluster 3, IPA predicted the following pathways in Cluster 3 to be upregulated: CD28 signalling in T-helper cells: (z=2.688), TREM1 signalling (z=4.123), B-cell receptor signalling (z=3.128), role of pattern recognition receptors in recognition of bacteria and viruses (z=4.00), role of NFAT in regulation of the immune response (z=3.578), iCOS-iCOSL signalling in T-helper cells (z=2.309).