CD4 and persistent truncus arteriosus: As reported earlier, cardiac pressure overload induces specific T cell activation in the mediastinal LNs (Figure 2a, 2b), and infiltrated CD4 T cells are major contributors to adverse cardiac remodeling and cardiac fibrosis.19–22 In addition, the microbiota profile of Tcra−/- TAC mice is significantly different from WT TAC mice and more closely resembles Sham mice (Figure 1a-1c).