ROCK1 and atrial fibrillation: The expression of ROCK1 protein (normalized to GAPDH) by immunoblotting in left atrial tissues of the MR AF patients (n = 6) was significantly higher than the expression of ROCK1 of the normal control subjects (n = 3) (0.170 ± 0.078 vs. 0.004 ± 0.003, p = 0.039) (Fig. 7b).