CXCL9 and myocarditis: Significantly, the intensity of the myocardial infiltrate was positively correlated with CXCL9 mRNA expression; moreover, a single nucleotide polymorphism in the CXCL9 gene, associated with a reduced risk of developing severe CCC in a cohort study, was associated with reduced CXCL9 expression and intensity of myocarditis in CCC [26].