Enables several functions, including phosphotyrosine residue binding activity; protein domain specific binding activity; and protein tyrosine phosphatase activity. Involved in epididymis development; negative regulation of interleukin-6 production; and negative regulation of tumor necrosis factor production. Acts upstream of or within several processes, including hemopoiesis; negative regulation of protein phosphorylation; and regulation of lymphocyte activation. Located in cell-cell junction. Part of alpha-beta T cell receptor complex. Is expressed in several structures, including central nervous system; retina; and thymus primordium. Orthologous to human PTPN6 (protein tyrosine phosphatase non-receptor type 6). [provided by Alliance of Genome Resources, Apr 2022]