• ArrayExpress is a database of functional genomics data supported by scientific publications.
  • The Gene Expression Atlas is a database providing information about gene expression in different biological conditions (for example in different cell types, organisms parts and disease states).
  • The difference between the two is that ArrayExpress is built around experiments and should be used to retrieve experiments and information about experiments (data files, sample annotation and others). The Atlas is built around genes and biological conditions; it should be used to visualise changes in gene expression  associated with different biological conditions.