I've a bunch of genes (~8000). Each of these genes has an associated p-value representing its "importance" in a specific biological pathway. Within these genes I'm interested in a subset of genes (~200). How can I test wheter these 200 genes are in the tail of the p-value distribution. In other terms, how can I test wheter these 200 genes are "more" significant than the rest of the genes. For now I did an hypergeometric test using a thresold on the p-value. Let's say :
A : Total genes (~8000) B : Subset of gene of interest (~200) C : Genes in A with p-values <= 0.05 D : Genes in B with p-values <= 0.05
but I have to define a thresold (0.05) ....
Edit : Can I do a Mann-Whitney U test on the p-values ? (comparing A vs B ; by removing the subset B from A of course)