目前的版本：Pfam 23.0 (July 2008, 10340 families)
The Pfam database is a large collection of protein families, each represented by multiple sequence alignments and hidden Markov models (HMMs).
3，NCBI的CDD（Conserved Domain Database）数据库
Proteins often contain several modules or domains, each with a distinct evolutionary origin and function. NCBI’s Conserved Domain Database is a collection of multiple sequence alignments for ancient domains and full-length proteins.