Non-Receptor Protein Tyrosine Phosphatase Genes encode Non-Receptor Protein Tyrosine Phosphatases, one of the two main categories (soluble and transmembrane receptor) of enzymes that catalyze removal of a tyrosine-attached phosphate group and are important in control of cell growth, proliferation, differentiation, and transformation. Two cysteines in the catalytic domain (one absolutely required for activity) are generally conserved; other conserved residues in the vicinity are important. (NCI) [ ]