S100A8 and infection: To further define the effect of tofacitinib on antimicrobial response, we measured expression of mucin 1 (Muc1) and antimicrobial proteins S100a8/S100a9 which contribute to C. jejuni colonization.20,21 Expression of Muc1 and S100a8/S100a9 was upregulated following C. jejuni infection, consistent with previous studies.20,21 Oral tofacitinib treatment after infection had no effect on S100a8 expression while Muc1 expression was downregulated and S100a9 expression showed a trend to reduction (Fig. 1H).