HER-2-E0771 cells generated to inducibly overexpress PTPN2 in response to doxycycline (E0771-HER-2-PTPN2hi) were pre-incubated (24 h) with vehicle or doxycycline (DOX) subsequently stimulated with IFNγ for the indicated times. STAT-1 Y701 phosphorylation (p-STAT-1) and PTPN2 levels were assessed by immunoblotting. 