Patients need to be screened for bradycardia, long QT, AV block, and other arrhythmia risk factors before initiation, the first dose must be given as an in-patient treatment for hourly blood pressure measurements, and cardiac monitoring for bradycardia from atrioventricular block (related to fingolimod binding to S1PR3) can occur. The gene discussed is S1PR3; the disease is atrioventricular block.