However, the observation that the activation of the RhoA/ROCK pathway in the dialysis patients with AF of our study is associated with an increased expression of Cx40, integral membrane protein of heart gap junctions, fundamental for the rapid cell–cell transfer of action potential, and that the increased MYPT-1 phosphorylation, the marker of ROCK activity, correlates with Cx40 in these patients adds more evidence for the involvement of the RhoA/ROCK pathway in the mechanistic interactions leading to generation/perpetuation of AF. This evidence concerns the gene GJA5 and atrial fibrillation.