Transfusion

Blood transfusion is the process of transferring blood or blood-based products from one person into the circulatory system of another. Blood transfusions can be life-saving in some situations.

Wolverine performed blood transfusions to try to use his mutant healing power to save others. However, it only worked twice.

When Leech was close to death, Storm and Jubilee convinced Logan to perform a transfusion even though he was unsure if it would help at all. It did help and Leech was fine.