Autopsy results in patients with rheumatic heart disease (n = 5) showed significantly higher cell counts of myeloid DC (CD11C+), migratory activated DCs (CD209+), mature DCs (CD80+), T lymphocytes, and M1 (CD68+) and M2 macrophages (CD163+) in the left atrium compared with those in the non-rheumatic heart disease group (n = 5) [50], indicating a role for atrial immune cells in rheumatic heart disease (Figure 1). Here, CD209 is linked to rheumatic heart disease.