Functional classification according to the GeneOntology (GO) reference of the mRNA activated by pituitary adenylate cyclase-activating polypeptide (PACAP) plus cycloheximide (biological process level three). Cluster analysis was conducted with the FatiGO application (http://www.fatigo.org). As illustrated with FBJ osteosarcoma-related oncogene (Fos), which belongs to six categories indexed in GO biological process level three (pattern specification, sex differentiation, embryonic development and organ development; metabolism; morphogenesis, cell differentiation and cell development; regulation of physiological process, organismal physiological process; regulation of cellular process and finally cellular physiological process), one particular gene can be assigned to several GO annotations.