Phase 2 – Data analysis

Determining if the genes are significantly differentially expressed, and noticing any expression patterns.

Statistical analysis

Raw expression data of selected genes (STAT2, OAS1, OAS2, OAS3) from each sample set (α,β,γ,δ) were compared in four pairwise sets to determine if foldchange between the samples was significant. Sample sets from the same source are “matched”; from different sources are “unmatched”. Matched pairs were analyzed using the Wilcoxon signed rank test; for significance, W≤0 is needed for n=6. Unmatched pairs were analyzed using the Mann‑Whitney U-test. For both analysis tests, significance level was p<0.05. All statistical analyses were made in Excel; charts were made in Excel and annotated using Inkscape.

Second-order comparison

Differential genetic expression (hereafter DGE) values were normalized relative to control sample δ (vehicle on non-asthmatic HAEC) and presented on a bar chart (Fig. 2), grouped by gene & colour-coded comparison sets (A,B,C,D). The ratio between each pair was calculated as their foldchange. Chart presentation style allowed for easy visual comparison of foldchange of the same gene between comparison sets (grouped) and of different genes in the same comparison set (coloured).