Fig. 6

Gene count ratio estimates identify the specific individuals previously identified by String-db analysis. Stable genes identified in three data sets were used to normalize gene expression (see Additional file 10). In panel a, the CBX3/ATG3 gene ratios of two highly stable genes are plotted for each of the 35 samples in our study. A 2-fold range of variation is noted between samples 8 and 14. In contrast, when two of the interferon regulated genes were normalized in relation to the ATG3 gene (panels b and c) samples 9, 6 and 12 were highlighted with ratios 2 to 5-fold higher than noted in panel a. The relative response profile of samples 9, 6 and 12 in panels b and c correspond to the genes correlated with IFIT3 gene previously identified in Fig. 3. In contrast to the IFIT3 and IFI44L response profiles, when the DEFA3 gene was normalized in relation to ATG3, samples 13, 34, 28 and 35 were highlighted. When evaluated in relation to highly stable genes within the data set, the nonlinear gene trendlines identified in our analysis highlight meaningful inter-individual changes in gene expression that cannot be explained on the basis of technical variation