Gene Description Variable Select the column containing gene descriptions from GenBank, Unigene, or Gene databases. It is used to make the web search link to PubMed and Entrez-Cross, if specified. To Select a Gene Description Variable: Specify an Input SAS Data Set . The Available Variables field is populated with variables from the specified data set. Left-click a variable from the Available Variables field. Click to add the selected variable to the Gene Description Variable field.