AGT and Hypertension: We then performed parabiosis experiments by conjoining non-fluorescent C57BL6/J mice with Myh11CreERT2; Rosa26Td mice and observed few Td+ cells in hearts from both PBS and Ang II treated C57BL6/J mice assessed by FACS analysis (Supplementary Fig. 3H), indicating that Myh11+ SM cells in the heart do not contribute to macrophage-like cells in this pathological process.Taken together, these indicate that hypertension induces circulating monocyte-derived macrophages, but not cardiac resident macrophages, to transition to myofibroblasts.