Within each study, for each disease and pathway/GO combination,
we calculate the relative risk from a two-by-two contingency table:
In Pathway X
Not in Pathway X
Regulated in Disease
Not Regulated in Disease
The regulation criteria are described in detail in the disease analysis section.
After computing the relative risk, a z-score is calculated (RR / Std.Error RR),
which is used to rank pathway/GO terms for their disease association.