The list of genes and ESTs represented on the arrays in the HG-U133 Set (HG-U133A and HG-U133B) can be obtained through the NetAffx™ Analysis Center. The HG-U133 probe set annotations (public accession numbers, gene ontology classifications, and protein annotations) are now available as part of the Affymetrix® Array Target Sequence group under the databank called HG-U133 Target.