It has been found that a main effect (immunosuppressive activity) of an S1P1 receptor agonist correlates with the selectivity for cells expressing a combination of an S1P1 receptor with Gαi2 or Gαi3, and that an adverse effect (cardiotoxicity) of an S1P1 receptor agonist correlates with the selectivity for cells expressing a combination of an S1P1 receptor with Gαi1.