Figure 2 Blockade of interferon γ (IFNγ)‐mediated inhibition of matrix metalloproteinase 13 (MMP13) by anti‐IFNγ receptor 1 antibody. Chondrocytes were incubated with IFNγR1 monoclonal antibody and control‐matched isotype (mouse IgG1) at 2 μg/ml for 1 h. Cells were treated as indicated. (A) MMP13 mRNA and (B) protein was determined. (C) Chondrocytes incubated with neutralising antibody for IFN‐γR1 (NAb) and mouse IgG1 for 1 h were subjected to different treatments for 5 min and harvested. Western blots showing complete elimination of signal transducer and activator of transcription (STAT)‐1 tyrosine (tyr) and serine (ser) phosphorylation by NAb are depicted. Lower panel shows STAT1 blot as loading control.