PRotein Ontology (PRO) Release 22.0 (29-Aug-2011)

There are 27566 PRO terms
    4 terms are in the 'organism-family' category.
   309 terms are in the 'family' category.
  18224 terms are in the 'gene' category.
  1386 terms are in the 'sequence' category.
  6034 terms are in the 'modification' category.
   99 terms are in the 'complex' category.
   455 terms are in the 'organism-gene' category.
   405 terms are in the 'organism-sequence' category.
   356 terms are in the 'organism-modification' category.
   172 terms are in the 'organism-complex' category.
   11 terms are in the 'union' category.
1569 terms have some kind of annotation, codifying the information from 1060 papers.
  2338 connections to GO (798 PRO terms).
   374 connections to MOD (327 PRO terms).
   604 connections to Pfam (362 PRO terms).
   338 connections to SO (317 PRO terms).
   306 annotations of a phenotype (299 PRO terms).

The ontology includes a subset of terms from other ontologies and resources that are used for logical definitions.

_Current changes_

None

_Forthcoming changes_

1) To comply with the standard set by the Human Genome Nomenclature Committee, we will replace the word "antigen" with "molecule" for terms related to cell differentiation (CD). For example, CD9 antigen (PR:000005178) will become CD9 protein. This change will take effect with the next release.

2) PRO will introduce inferred complexes. Inferred complexes are those that lack experimental evidence in an organism even though that organism is known to contain orthologs (or ortho-isoforms/ortho-modified forms) of every component of the complex found in another organism. Such complexes will be flagged with the evidence code ECO:0000088 ("Biological system reconstruction"). Such complexes will appear in the next release.

3) PRO terms will each receive shorthand labels. These labels are meant to facilitate the ability to view the terms using software such as Cytoscape, where space is limited. The labels will begin appearing in the next release.