Heart grafts from mice without anti-IL-6 showed severe signs of cellular rejection, including extensive lymphocytic infiltrations, myocardial fibrosis, and necrosis, while three of four grafts from anti-IL-6 treatment demonstrated only mild to moderate signs of rejection, including lower rates of pericardial inflammation and intima arteritis (Figure 2B). Here, IL6 is linked to Myocardial fibrosis.