Updated publication reference for PubMed record(s): 26479789. In the related study, to determine whether DUSP2 definitively served as a phosphatase for STAT3, an in vitro phosphatase assay was used. Using S-tag beads, p-STAT3 was pulled down from IL-6 stimulated HEK293T cells transfected with STAT3-S-Tag. DUSP2 or control protein, which was purified from HEK293T cells transfected with DUSP2-FLAG or empty vector through extraction with anti-FLAG beads and elution with FLAG peptides, were incubated with p-STAT3-S-Tag-beads in phosphatase buffer. Then bound proteins were eluted and subjected to MS analysis. When compared with the control, incubation of STAT3 and DUSP2 led to dephosphorylation of two STAT3 residues that have been reported to promote its activity, namely tyrosine 705 and serine 727.