FOS and atrial fibrillation: Notably, all candidate mechanosensitive genes assessed (Cox2, Myc, Fos) were significantly upregulated compared to the unloaded controls at 6 hours following exposure of AF cells to acute CTS at 2.0 Hz (fold change (Cox2) = 2.3 ± 0.45, fold change (Myc) = 1.5 ± 0.07, fold change (Fos) = 1.6 ± 0.13; Figure 8D).