Once we have a set of genes/proteins in the required format, it is extremely interesting to annotate them with their roles in biology via functional enrichments such as GO terms. The aim of enrichment is to find a significant set of functions (here, we use GO terms or pathways in the case of pathway enrichment) for the given genes.
Enrichment is achieved by looking for the over-representation of GO terms within the group of genes. The significance of over-representation is calculated with statistical tests such as the Fisher test.
Talking about GO, pathways, and statistical tests, is beyond the scope of this book; refer to the relevant citations for details.
The following are the prerequisites to go ahead with ...