PRotein Ontology (PRO) Release 15.1 (10-Feb-2011)

There are 26300 PRO terms
   304 terms are in the 'family' category.
  18200 terms are in the 'gene' category.
  1244 terms are in the 'sequence' category.
  5704 terms are in the 'modification' category.
   35 terms are in the 'complex' category.
   243 terms are in the 'organism-gene' category.
   236 terms are in the 'organism-sequence' category.
   146 terms are in the 'organism-modification' category.
   68 terms are in the 'organism-complex' category.
    8 terms are in the 'union' category.
1519 terms have some kind of annotation, codifying the information from 977 papers.
  2139 connections to GO (748 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.