TBX5 and atrial fibrillation: Several TFs associated with AF were also dysregulated in the LA after Notch activation, including the direct Notch target Hes1 (5.17 ± 0.053, P < 0.00000001), Tbx5 (0.79 ± 0.078, P < 0.05), and Pitx2 (1.5 ± 0.11, P < 0.001) (Figure 4D, Supplemental Table 14).