PANTHER: a browsable database of gene products organized by biological function, using curated protein family and subfamily classification. Thomas P.D., Kejariwal A., Campbell M.J., Mi H., Diemer K., Guo N., Ladunga I., Ulitsky-Lazareva B., Muruganujan A., Rabkin S., Vandergriff J.A., Doremieux O. Nucleic Acids Res. 2003;31:334–341. doi: 10.1093/nar/gkg115.
The authors would like to add the following text to the end of the Abstract: The ontology terms and protein families and subfamilies, as well as Drosophila gene classifications, can be browsed and searched for free. Due to outstanding contractual obligations, access to human gene classifications and to protein family trees and multiple sequence alignments will temporarily require a nominal registration fee.