Encoded by Protein Tyrosine Phosphatase Genes, Protein Tyrosine Phosphatases are a group of enzymes that specifically remove tyrosine-bound phosphate groups from many phosphoproteins, including many enzymes phosphorylated by a tyrosine kinase. Together with protein tyrosine kinases, Tyrosine Phosphatases regulate tyrosine phosphorylation and dephosphorylation in cellular signal transduction and may play a role in cell growth control and carcinogenesis. (NCI)