Key pathways that increase CVB3 myocarditis in males include Toll-like receptor (TLR)4 signaling on cardiac mast cells and macrophages, and inflammasome activation, which lead to elevated interleukin (IL)-1β levels that increase inflammation and remodeling/fibrosis, resulting in acute myocarditis and progression to DCM in white background mice (i.e., BALB/c, A/J) (14, 22, 23). Here, TLR4 is linked to myocarditis.