PRotein Ontology (PRO) Release 45.0 (07-Apr-2015)

There are 223338 PRO terms in the Protein Ontology.
   54 terms are in the 'external' category.
   368 terms are in the 'family' category.
  23581 terms are in the 'gene' category.
  8306 terms are in the 'sequence' category.
  6668 terms are in the 'modification' category.
   214 terms are in the 'complex' category.
   16 terms are in the 'organism-family' category.
 114946 terms are in the 'organism-gene' category.
  66948 terms are in the 'organism-sequence' category.
  1608 terms are in the 'organism-modification' category.
   374 terms are in the 'organism-complex' category.
   38 terms are in the 'union' category.
2376 terms have some kind of annotation, codifying the information from 1583 papers.
  4198 connections to GO (1572 PRO terms).
   292 connections to MOD (255 PRO terms).
   620 connections to Pfam (373 PRO terms).
   338 connections to SO (317 PRO terms).
   349 annotations of a phenotype (342 PRO terms).

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

_Forthcoming changes_

1) Starting on Release 47 the format for the PAF file will change. Columns number 15 (Protein_region) and 16 (Modified_residue(s), MOD_ID) will be removed, as all the information about the region and modification are now contained in the ontology file. 

2) Continue to add shorthand labels to terms.

3) Resolve names and synonym duplicates.