STAT3 inhibition was effective (Supporting Information Fig S1A and B) and resulted in protection of mice from myocarditis, as shown by the significantly reduced percentages of heart-infiltrating CD11b+ cells at sacrifice (Fig 1A) and by virtually undetectable lymphocyte infiltration as assessed by H&E and anti-CD18 staining (Fig 1B). Here, ITGB2 is linked to myocarditis.