CD68 and atrial fibrillation: CD68-staining for M1 ΜΦs and CD163-staining for M2 ΜΦs confirmed that short τm cells with high TPE-AF intensity were, indeed, M1 ΜΦs (Figure 3b) and that cells with longer τ1, τ2, and τm with low TPE-AF intensity were, indeed, M2 ΜΦs (Figure 3d, Figure 3—figure supplement 1, Table 1).