to random chance alone, IPA applies a Fisher’s exact test. The network score or P-value represents the significance of the focus gene enrichment. There are 25 diseases and disorders categories and 32 molecular and cellular function categories in the IPA Knowledge base. Enrichment of focus genes to these diseases and functional categories was also evaluated. The P-value, based on a right-tailed Fisher’s exact test, considers the number of identified focus genes and the total number of molecules known to be associated with these categories in the IPA knowledge database.
