STAT1 and breast carcinoma: In contrast, heparin inhibited the stimulatory effect of IFN-γ on the production of CXCL9 and CXCL10 by human breast cancer cells by inhibiting cellular IFN-γ binding and modulating the IFN-γ-induced signal transducer and activator of transcription 1 (STAT1) phosphorylation (194).