These are the first tests of a treatment in humans and involve approximately 15–30 people. They aim to see if the trial treatment is safe and to find the best dose. The research team notes major and minor side effects. This helps researchers to work out the best dose and the best way to give the trial treatment. Phase 1 trials are usually only suitable for people with incurable cancer who have had all the known effective treatments for their cancer. People take part in these trials in the hope that the treatment may extend their life or improve their quality of life. Most often though, the reason to enter Phase 1 trials is to help people with cancer in the future.  If a Phase 1 trial shows that the new treatment is safe it will go on to Phase 2 testing.