Animal studies indicate that myocarditis can progress to heart failure and dilated inflammatory cardiomyopathy, not via interleukin-5 (IL-5) - a key pro-inflammatory cytokine responsible for driving eosinophil differentiation and maturation from progenitor cells, but rather through eosinophil-derived interleukin-4 (IL-4) [13]. The gene discussed is IL4; the disease is myocarditis.