Background: We have RNA-seq data (a method to quantify the expression of genes in a cell) from different cell types. These data were normalized using a method called TMM and then log2-transformed followed by Z-transformation.
We then plotted the Z-scores for two groups of genes as shown in the plot below for two cell types.
We aim to establish that the difference in expression between the two cell types is greater for genes in group 1 than for those in group 2.
wilcox.test on both groups results in highly significant p-values <
0.00000000000000022 so comparing these two p-values is not too informative.
Would there be a more elaborate way to establish this difference?