What is the link between medical ethics and law?

There are a lot of ways to interpret this. In short, medical ethics are principles that doctors or healthcare professionals should do what is right ethically. For example, the 4 pillars of ethics indicates do no harm to patients. The link between medical ethics and law is that law provides the boundary of what is the right or wrong thing to do legally. There are a lot of complications to this as for example a doctor could give morphine to reduce pain, but giving it excessively might cause harm to the patient and this might be bound by the law if the intention is wrong.