Given that synovitis in our model was induced by injection of LPS, it is not surprising that “antigen processing and presentation of polysaccharide antigen via MHC class II” was a dominant BP in the brown module, particularly considering that IFN-γ was not detected by immunoassay in conditioned SF or ISF in a preliminary screening performed in our study (50). This evidence concerns the gene IFNG and synovitis.