Dephosphorylates a range of proteins, and thereby regulates cellular signaling cascades (PubMed:17070019). Dephosphorylates cellular tyrosine kinases, such as ERBB2 and PTK2B/PYK2, and thereby regulates signaling via ERBB2 and PTK2B/PYK2. Selectively dephosphorylates ERBB2 phosphorylated at 'Tyr-1112', 'Tyr-1196', and/or 'Tyr-1248' (By similarity). H2O + O-phospho-L-tyrosyl-[protein] = L-tyrosyl-[protein] + phosphate Interacts with PSTPIP1 and TGFB1I1 (PubMed:10092676, PubMed:11711533). Interacts with PTK2B/PYK2 (PubMed:12674328). Interacts with LPXN (PubMed:12674328, PubMed:15786712). Interacts with SORBS2; this interaction greatly enhances WASF1 dephosphorylation and might mediate partial translocation to focal adhesion sites (By similarity). Partial translocation to focal adhesion sites might be mediated by interaction with SORBS2. Phosphorylated by STK24/MST3 and this results in inhibition of its activity. Complete embryonic lethality at 9.5 to 10.5 dpc. Heterozygous mice have no obvious phenotype. Belongs to the protein-tyrosine phosphatase family. Non-receptor class 4 subfamily.