PRotein Ontology (PRO) Release 19.0 (25-May-2011)

There are 26999 PRO terms
    4 terms are in the 'organism-family' category.
   304 terms are in the 'family' category.
  18201 terms are in the 'gene' category.
  1357 terms are in the 'sequence' category.
  5914 terms are in the 'modification' category.
   62 terms are in the 'complex' category.
   356 terms are in the 'organism-gene' category.
   363 terms are in the 'organism-sequence' category.
   207 terms are in the 'organism-modification' category.
   110 terms are in the 'organism-complex' category.
    9 terms are in the 'union' category.
1550 terms have some kind of annotation, codifying the information from 1035 papers.
  2295 connections to GO (779 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.