PTPRC and Interstitial cardiac fibrosis: Based on previous work, we propose that interstitial cardiac fibrosis arises from immune‐inflammatory dysregulation: We have shown that Ang‐II resulted in the upregulation of MCP‐1 within 1 day of infusion, which corresponded with the appearance of CD45+ monocytic cells that polarized into cytokine‐producing M1 cells.