May be involved in growth and differentiation of hematopoietic cells. H2O + O-phospho-L-tyrosyl-[protein] = L-tyrosyl-[protein] + phosphate Interacts with PSTPIP1. Highest expression in bone marrow. Also expressed in kidney, lung, ovary, spleen, thymus and lymph node. Expressed in the embryo from day 15.5. Belongs to the protein-tyrosine phosphatase family. Non-receptor class 4 subfamily.