PRotein Ontology (PRO) Release 12.0 (21-Jul-2010)

There are 25656 PRO terms
  277 terms are in the 'family' category.
  18182 terms are in the 'gene' category.
  1144 terms are in the 'sequence' category.
  5643 terms are in the 'modification' category.
  144 terms are in the 'organism-gene' category.
  107 terms are in the 'organism-sequence' category.
  33 terms are in the 'organism-modification' category.
  13 terms are in the 'complex' category.
  9 terms are in the 'organism-complex' category.
1436 terms have some kind of annotation, codifying the information from 926 papers.
 1995 connections to GO (685 PRO terms).
 361 connections to MOD (317 PRO terms).
 599 connections to Pfam (358 PRO terms).
 325 connections to SO (307 PRO terms).
 296 annotations of a phenotype (289 PRO terms). 

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

_Changes from Release 11.0_

1) PRO is now aligned with the Basic Formal Ontology (BFO), and therefore the root nodes changed from previous release. For example, "amino acid chain" and "protein complex" will be children of the BFO term "object" while "immature protein part" and "modified amino acid residue" will be children of "fiat_object_part" (both BFO terms are "material_entity").