PRotein Ontology (PRO) Release 16.0 (25-Feb-2011)

There are 26592 PRO terms
   304 terms are in the 'family' category.
  18200 terms are in the 'gene' category.
  1281 terms are in the 'sequence' category.
  5865 terms are in the 'modification' category.
   39 terms are in the 'complex' category.
   270 terms are in the 'organism-gene' category.
   280 terms are in the 'organism-sequence' category.
   155 terms are in the 'organism-modification' category.
   78 terms are in the 'organism-complex' category.
    8 terms are in the 'union' category.
1541 terms have some kind of annotation, codifying the information from 1027 papers.
  2271 connections to GO (770 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.