Although Gq-coupled M1-receptors seem to regulate human atrial IK, Ach, which is likely to be augmented in patients with long-standing persistent atrial fibrillation [99], we did not reveal a clear insight into the implication of the M1-receptor in the 1,2-NQ-mediated right atria disturbances. The gene discussed is FGFR3; the disease is atrial fibrillation.