Protein phosphatases remove phosphates from proteins, usually on Serine, Threonine, and Tyrosine residues, reversing the action of protein kinases. The PTP family of protein phosphatases is tyrosine-specific, and several other families (PPPL, PPM, HAD) appear to be serine/threonine specific, while other families are unknown or have a variety of substrates (DSPs dephosphorylate any amino acid, while some protein phosphatases also have non-protein substrates). In the human genome, 20 different folds of protein are known to be phosphatases, of which 10 include protein phosphatases.
Protein phosphatomes have been cataloged for human and 8 other key eukaryotes, for Plasmodium and Trypanosomes
and phosphatomes have been used for functional analysis, by experimentally investing all known protein phosphatases, in the yeast Fusarium, in Plasmodium  and in human cancer
Large scale databases exist for human and animal phosphatomes [http://phosphatome.net/wiki/index.php Phosphatome.net], parasitic protozoans [http://202.41.10.46/ProtozPhosDB/ ProtozPhosDB] and for the substrates of human phosphatases [http://www.koehn.embl.de/depod/ DEPOD].